Taking carnitine with omega-3 fish oil is one of the simplest things you can do to lose weight and raise your energy levels. The cool thing about carnitine is that by elevating the amount of carnitine stored in your muscles, you will see improvements in your quality of life. Fat loss and more energy are two of these benefits, but taking carnitine is known to improve all of the following:

•    High-intensity work capacity
•    Increase athletic performance
•    Speed your recovery from intense exercise
•    Make your brain work better
•    Prevent oxidative stress that leads to longer term health problems such as cardiovascular disease, diabetes, and chronic inflammation

A recent study in The Journal of Physiology provides groundbreaking evidence that carnitine supplementation can improve athletic performance, something that researchers have had trouble proving for years. Emerging research on the benefits of carnitine for health in conjunction with evidence that clarifies the best ways to take carnitine (insulin must be present in the body for carnitine to be delivered into the muscle), make it time to revisit this amino acid. Let’s look at the top ten health benefits of elevating your carnitine levels with a focus on achieving optimal body composition.

1)    Take Carnitine to Burn Fat: The Basics
Carnitine is an amino acid composite that is made from lysine and methionine. There are a couple of different forms of carnitine, such as acetyl-L-carnitine and L-carnitine tartrate, and we’ll look at which forms you should be taking and when. In this article, unless otherwise stated,  “carnitine” will be used to refer to L-carnitine tartrate.
 
Carnitine is a potent fat burner because it is responsible for the transport of fats into the cells to be used for energy in the body. By raising the level of muscle carnitine, you support the fat burning process, and because your body becomes more efficient at processing fuel, it will increase your energy levels. Elevating carnitine will also improve physical performance by burning more fat, sparing glycogen, clearing muscle lactate, and increasing anabolic hormone response.
 
2)    Pair Carnitine and Omega-3 Fish Oils For Fat Loss
For carnitine to be effective, you need to ensure you have adequate levels of omega-3 fish oils in the body. In order for your body to actually “load” carnitine that you take in supplement form into the muscles where you want it, it has to be accompanied by insulin.
 
Omega-3 fatty acids come into the equation because they will improve the health of every cell in your body if you get enough of them. The cells are made up of two layers of lipids or fats, which will be composed of good fats or bad fats depending on the type you eat. If the cell lipid layers are made up of omega-3s, the cell will be generally healthier, and it will also make them more sensitive to insulin. Having your cells be more sensitive to insulin allows your body to get the most energy production out of supplemental carnitine.
 
I mention this relationship between omega-3s and carnitine because you won’t optimally benefit from taking carnitine unless you have already attended to your omega-3s. In working with obese clients, I’ve found that using high doses of fish oil with carnitine tartrate will allow the fat to start to come off.
 
Omega-3s increase metabolic rate by increasing cell activity and fat burning. Carnitine is the delivery system for long chain fatty acids such that the less carnitine you have in the body, the fewer fatty acids that get into the cell, meaning you don’t burn them for energy. Instead, the fatty acids go into a depository and are stored as fat. By elevating carnitine, fat burning increases and you give the cell the right genetic machinery to raise metabolism. You’ll have more energy, feel more motivated, and any excess fat begins to come off.
 
3)    No Need For Carbs: Carnitine with Omega-3s for Fat Loss
The new study in The Journal of Physiology, which we will highlight below starting with #5, showed that taking carnitine with carbs is effective for elevating muscle carnitine levels and improving athletic performance. But carbs aren’t necessary as long as you get adequate omega-3s. A study in the Annals of Nutrition and Metabolism showed that combining carnitine, omega-3s, and polyphenols resulted in lower blood lipid levels and better cellular energy production, which has the implication of fat loss if the study had been of longer duration—it was only 12 weeks.
 
Researchers found that triglycerides were lowered by 24 percent and free fatty acids decreased by 29 percent compared to a placebo group that had no changes. These changes indicate healthier markers of cholesterol, better energy use, and fat burning that will lead to fat loss. Additionally, genes that increase fat burning in the body were “activated” indicating a better metabolic profile. Take note that the polyphenols were included to raise antioxidant levels and fight oxidative stress that leads to chronic inflammation and poor cardiovascular health, among other things. They are not necessary for the carnitine to work its magic.
 
4)    Carnitine Fights Visceral Belly Fat
Visceral belly fat is one of the toughest fats to lose once you’ve got it, and it causes numerous health problems. Once you begin to gain visceral fat around the belly, it will lead to fat gain within the organs such as the liver, the heart, or even in muscle. Fat gain in the liver leads to non-alcoholic fatty liver disease, while epicardial fat is a type of visceral fat that is deposited around the heart and is considered a metabolically active organ, altering heart function.
 
Raising your carnitine levels will fight this visceral fat gain because it increases fat burning, which has the effect of taking triglycerides and low-density lipoproteins out of the system so that they don’t build up causing high cholesterol and atherosclerosis. A new research study in the journal Food and Chemical Toxicology illustrates this. Researchers gave a carnitine supplement to mice who were fed a high-fat diet in order to make them gain weight. In comparison to a group of mice fed a placebo, the carnitine group gained substantially less visceral and subcutaneous fat (fat that is right below the surface of the skin that you can pinch with your fingers). The placebo group exhibited the beginning stages of non-alcoholic fatty liver disease and atherosclerosis, neither of which were evident in the carnitine group.
 
5)    Take Carnitine To Improve Performance
The study in The Journal of Physiology is the first to show that muscle carnitine content can be increased in humans through diet . Once carnitine is elevated, metabolism in the body is dependent on the intensity of exercise, allowing for better energy use and performance.
 
Researchers gave a placebo or a supplement of carnitine tartrate and carbs (2 g carnitine with 80 g of carbs twice a day) to experienced athletes who were training for a triathlon three to five times a week. At various points throughout the study subjects performed the following exercise tests: two thirty-minute repeated bouts of exercise (the first at 50 percent of maximal oxygen uptake and the second at 80 percent), followed by an all-out 30-minute performance trial.
 
After 24 weeks of supplementation, the carnitine group increased performance from baseline by 11 percent in the exercise trials compared to no improvement in the placebo group. Participants who took carnitine also rated the trial and the exercise bout they performed at 80 percent of max to be easier than at baseline, while the placebo had no difference in rating of perceived exertion (RPE).
 
Two key points from this study are essential for making carnitine supplementation effective at elevating performance. First, it takes a long supplementation period to raise muscle carnitine levels and reap the benefits of improved energy production. In this study after three months there were no changes in performance or RPE from baseline, but after 6 months those improvements were pronounced and statistically significant. Somewhere between 3 and 6 months is the magic number, meaning taking carnitine is a lifestyle supplement just like omega-3s are.
 
Second, carnitine doesn’t accumulate or “load” in muscle unless accompanied by high insulin concentrations. This explains why many previous studies have NOT shown increases in muscle carnitine after taking it in multi-gram doses. In this study the carnitine was taken with carbs because the carbs triggered insulin release, which allowed the carnitine to load into the muscle. Take note that there is a big focus in the health world on minimizing insulin secretion from carbs for optimal body composition. This is critical, but be aware that insulin is actually a potent anabolic hormone if the cells are sensitive to it and if appropriate levels are present.
 
Pairing carnitine with carbs is one option, but as shown in #3, carnitine can also be paired with omega-3s, which may be more appropriate for individuals whose primary goal is to lose fat. In my experience, best fat loss results come from a 5 to 1 ratio of omega-3s to carnitine. If you’re taking 20 grams of omega-3s, you’d pair it with 4 grams of carnitine. But, if you’re more conservative with your omega-3 supplementation, you can start with 1 to 2 grams of carnitine and work up to 4 grams, which was the dose used in this study.
 
6)    Increase Work Capacity With Carnitine
Another benefit of raising carnitine levels is that you’ll have a greater work capacity, but it will not feel as physically difficult.  You’ll be able to lift more weight, complete more reps, or run faster and longer, but with more ease. This is because higher muscle carnitine levels help decreases pain, muscle damage, and markers of metabolic stress from high-intensity exercise by decreasing lactic acid production.
 
A higher level of carnitine increases energy production, but it also has the effect of accelerating muscle buffering by maintaining the pH of the muscle and minimizing the accumulation of hydrogen ions.  Basically, carnitine helps eliminate the byproducts of intense exercise that cause pain and muscle damage (the burning you may feel when training hard), allowing you to work harder.
 
In the Journal of Physiology study, results show how higher muscle carnitine levels increase work capacity by reducing lactate accumulation in the muscles. Following the exercise bout at 80 percent of maximal, muscle lactate buildup was 44 percent lower in participants that supplemented with carnitine compared to the control group. Following the exercise bout at 50 percent of maximal, the carnitine group used 55 percent less muscle glycogen than the control group indicating that they burned more fat for fuel and had improved energy production. ??
 
The combination of less lactate buildup and greater fat burning in the two exercise bouts allowed the carnitine group to increase work output by 35 percent, while having a lower RPE.  In simple terms, taking carnitine is a no-brainer if you want to improve body composition by burning more fat and be able to train at a higher level!
 
7)    Enhance Recovery with Carnitine
Take carnitine to speed both short- and long-term recovery from intense training and you’ll have less pain, soreness, and feel more energized. Muscle lactate buildup is a limiting factor that inhibits performance and causes muscle pain, meaning that if you produce less of it and are able to clear it faster, you will have a faster recovery.
 
Taking carnitine will also support an anabolic response to exercise by up-regulating the androgen receptors, which will “help to mediate quicker recovery,” according to one research group. Two studies led by William J. Kraemer tested the hormonal response to taking carnitine tartrate. In one of these studies, supplementing with carnitine for 21 days produced an increase in the resting content of the androgen receptors that bind with testosterone, indicating a better anabolic environment. Following resistance exercise, participants also had increased androgen receptor content that indicated greater cellular uptake of testosterone and increased protein synthesis. Enhanced protein synthesis allows tissue that was damaged during training to regenerate faster and speed recovery.
 
The second study also had participants take carnitine or a placebo for 21 days and found that after intense resistance training, the carnitine group had reduced muscle tissue damage (assessed by MRI) and increased IGFBP-3 levels (a binding protein that promotes tissue synthesis). Researchers suggest carnitine supplementation helps promote recovery  by producing “more undamaged tissue, (and a) greater number of intact receptors that would be available for hormonal interactions.”
 
8)    Improve Cognitive Performance with Acetyl-L-Carnitine and Increase Motivation
A form of carnitine called acetyl-l-carnitine will give you superior brain function and increase motivation, meaning it’s a great supplement for people who want to lose weight but feel unmotivated to exercise. Acetyl-l-carnitine helps DHA omega-3 fish oils work their magic on the brain—just like carnitine tartrate, this form needs to be taken with omega-3s in order to facilitate fat burning for energy in the brain.

Acetyl-l-carnitine is a powerful antioxidant and can detoxify the brain of heavy metals we suggest pairing it with Alpha Lipoic Acid along with DHA because all together they support dopamine levels, while increasing attention span and motivation. For depressed people or those who need to lose weight, it works wonders on motivation and self-initiative, both with training and work-related tasks. And by taking acetyl-l-carnitine, you’ll still benefit from improved energy, physical performance, work capacity, and a speedy recovery, all benefits to help you achieve a lean physique.
 
A number of research studies support the use of acetyl-l-carnitine for a better brain. For example, a new study in the Scandinavian Journal of Gastroenterology found that giving patients with liver dysfunction acetyl-l-carnitine significantly improved their physical function, general health, overall mood, and well-being. They also reported less depression and anxiety.
 
9)    Prevent Type 2 Diabetes and Improve Insulin Health With Carnitine
Carnitine is emerging as a supplement that can prevent type 2 diabetes because of how it improves fat metabolism. It can counter the diseases of metabolic syndrome by preventing  atherosclerosis, and supporting cardiovascular health, while inducing fat loss.
 
Plus, raising carnitine levels will fight related type 2 diabetes factors because it has antioxidant properties, meaning it abolishes free radicals and reduces oxidative stress.  The key to improving your insulin health and losing fat with carnitine is to understand that the following interrelated factors must be present for this method to be effective:
A)    Take carnitine with omega-3 fish oils. Remember, a 1 to 5 ratio is suggested.
B)    Adopt this supplementation protocol as a lifestyle habit, not a one time thing. Research shows androgen receptors are up-regulated after three weeks, triglycerides are improved after three months, but muscle carnitine level isn’t elevated for close to six months.
C)    A high-protein diet and exercise will make it much more effective
 
10)    Carnitine Supplementation Counters Cachexia or Wasting Disease
Raising carnitine levels can counter cachexia or wasting syndrome that is associated with diseases including cancer, AIDS, heart disease, and lung disease. Although this is not a common problem among the Poliquin readership, it should be mentioned here because carnitine supplementation is able to restore metabolic parameters in individuals with cachexia and thereby help fight the progression of life-threatening diseases.
 
Cachexia is characterized by progressive weight loss, muscle loss, cognitive decline, poor insulin health, inflammation, and poor organ function, among other things. Emerging evidence shows that in patients with cancer cachexia, carnitine is depleted and metabolism is impaired. A new study in Nutrition Journal  found that giving carnitine to men with pancreatic cancer who were suffering from cachexia improved their lean mass, increased energy metabolism, and improved their quality of life. Using carnitine produced a trend to increased survival over the course of the study and towards reduced hospital stays.

11)      Take Carnitine to Improve Male Fertility
Having adequate carnitine levels has been shown to be necessary for male fertility. One study found that fertile males had higher levels of carnitine and this was associated with healthier sperm. The men who were classified as infertile had lower carnitine and compromised sperm health. This study suggests that ensuring you have get adequate carnitine in conjunction with healthy lifestyle practices can support fertility.

12)      Use Carnitine for Better Skin
A topical carnitine cream can improve the health of your skin by decreasing the amount of oil released by the pores. A new study in the Journal of Cosmetic Dermatology found that a carnitine cream increased the amount of fat that entered the cell, which decreased the oil secreted by the skin. This led to less oily skin and a smoother overall appearance. It also indicates the value of using carnitine to improve the transport of carnitine across the cellular wall to be burned for fat because Beta fat oxidation, or burning, was enhanced.
 

In humans, vitamin C is essential to a healthy diet as well as being a highly effective antioxidant, acting to lessen oxidative stress; a substrate for ascorbate peroxidase;

Collagen, carnitine, and tyrosine synthesis, and microsomal metabolism
Ascorbic acid performs numerous physiological functions in human body. These functions include the synthesis of collagen, carnitine and neurotransmitters, the synthesis and catabolism of tyrosine and the metabolism of microsome. Ascorbate acts as a reducing agent (i.e. electron donor, anti-oxidant) in the above-described syntheses, maintaining iron and copper atoms in their reduced states.

Vitamin C acts as an electron donor for eight different enzymes: These reactions add hydroxyl groups to the amino acids proline or lysine in the collagen molecule via prolyl hydroxylase and lysyl hydroxylase, both requiring vitamin C as a cofactor. Hydroxylation allows the collagen molecule to assume its triple helix structure and making vitamin C essential to the development and maintenance of scar tissue, blood vessels, and cartilage.


2 are necessary for synthesis of carnitine. Carnitine is essential for the transport of fatty acids into mitochondria for ATP generation.
The remaining three have the following functions in common but do not always do this:
dopamine beta hydroxylase participates in the biosynthesis of norepinephrine from dopamine.
another enzyme adds amide groups to peptide hormones, greatly increasing their stability.
one modulates tyrosine metabolism.
Antioxidant
Ascorbic acid is well known for its antioxidant activity. Ascorbate acts as a reducing agent to reverse oxidation in aqueous solution. When there are more free radicals (Reactive oxygen species) in the body versus antioxidant, a human is under the condition called Oxidative stress. Oxidative stress induced diseases encompass cardiovascular diseases, hypertension, chronic inflammatory diseases and diabetes The plasma ascorbate concentration in oxidative stress patient (less than 45 µmol/L) measured is lower than healthy individual (61.4-80 µmol/L) According to McGregor and Biesalski (2006). This reaction can generate superoxide and other ROS. However, in the body, free transition elements are unlikely to be present while iron and copper is bound to diverse proteins. thus, ascorbate as a pro-oxidant is unlikely to convert metals to create ROS in vivo.

Immune system
Some advertisements claim that Vitamin C "supports" or is "important" for immune system function. These claims are partially supported by the scientific evidence (see Chandra RK, 1997, "Nutrition and the immune system: an introduction". The American Journal of Clinical Nutrition 66 (2): 460S–463S. PMID 9250133.)

Beta carotene is a member of the carotenoid family belonging to the isoprenoid compounds, which are polyunsaturates with antioxidant properties. The formula for beta carotene is C40H56 and it can exist as cis- or trans-isomers. Most of the naturally-occurring and synthesized forms of beta exists as the all-trans isomer.

Where is beta carotene found?

Beta carotene is produced by plants and microorganisms, with the main sources being yellow or orange and green-leaved vegetables or fruits such as sweet potato, spinach, carrots, pumpkin, butternut squash and apricots.

Beta carotene is also available as supplements, which may be synthetic or derived from palm oil, algae or fungi. When taken as a vitamin or mineral supplement, the dose ranges form 0.4 mg to 20 mg per day.

When used as a medicine to treat vitamin A deficiency, a dose of up to 6 mg/day may be given and in cases of erythropoietic protoporphyria (EPP), up to 300 mg/day may be taken. Beta carotene is also widely used as a yellow colouring agent (EC160a) in food and drink.

Although beta carotene is not classed as an essential nutrient, it is a precursor to vitamin A and the recommended daily intake is expressed as part of the reference nutrient intake (RNI) for vitamin A as retinol equivalents (RE).

Beneficial effects of beta carotene

As a provitamin of vitamin A, the importance of beta carotene in an individual depends on their level of pre-formed vitamin A. It is therefore difficult to define a beta- carotene deficiency. Beta carotene also interacts with other carotenoids during absorption and metabolic processes.

Studies have shown an association between high dietary intake of beta carotene and a reduced risk of heart disease and cancer. This may be due to the antioxidant properties of the molecule.

Properties

The absorption of beta carotene is facilitated by dietary fats and bile salts in the small intestine. Around 10% to 90% of the total dietary beta carotene is thought to be absorbed in the gut, with absorption decreasing, the higher the intake is. Low fat diets also reduce the amount of beta carotene absorbed.

Smokers have a low blood level of beta carotene, as do individuals with a high alcohol intake and those with HIV infection. People with impaired fat absorption from diet due to conditions such as jaundice, liver cirrhosis and cystic fibrosis also have a low blood level of beta carotene. Beta carotene is excreted in the feces and sweat.

Reviewed by Sally Robertson, BSc

Sources

http://www.crnusa.org/safetypdfs/003CRNSafetybetacarotene.pdf

http://www.sunchlorellausa.com/pressroom/pdf/PR_10Facts%20About%20Beta%20Carotene.pdf

http://www.food.gov.uk/multimedia/pdfs/evm_bcarotene.pdf

http://www.govita.com.au/library/Vitamins/VitaminBetacarotene.pdf

http://www.mccordresearch.com/sites/default/files/pdf/Multivitamin/Multi-Vitamin-A.pdf

http://www.nal.usda.gov/fnic/DRI/DRI_Vitamin_C/325-382_150.pdf

http://www.usp.org/sites/default/files/usp_pdf/EN/USPNF/beta_carotene.pd

Vitamin B12 is a nutrient that helps keep the body's nerve and blood cells healthy and helps make DNA, the genetic material in all cells. Vitamin B12 also helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak.

Two steps are required for the body to absorb vitamin B12 from food. First, hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body. Some people have pernicious anemia, a condition where they cannot make intrinsic factor. As a result, they have trouble absorbing vitamin B12 from all foods and dietary supplements.
Table of Contents

    What is vitamin B12 and what does it do?
    How much vitamin B12 do I need?
    What foods provide vitamin B12?
    What kinds of vitamin B12 dietary supplements are available?
    Am I getting enough vitamin B12?
    What happens if I don't get enough vitamin B12?
    What are some effects of vitamin B12 on health?
    Can vitamin B12 be harmful?
    Are there any interactions with vitamin B12 that I should know about?
    Vitamin B12 and healthful eating
    Where can I find out more about vitamin B12?
    Disclaimer

How much vitamin B12 do I need?

The amount of vitamin B12 you need each day depends on your age. Average daily recommended amounts for different ages are listed below in micrograms (mcg):
Life Stage     Recommended Amount
Birth to 6 months    0.4 mcg
Infants 7–12 months    0.5 mcg
Children 1–3 years    0.9 mcg
Children 4–8 years    1.2 mcg
Children 9–13 years    1.8 mcg
Teens 14–18 years    2.4 mcg
Adults    2.4 mcg
Pregnant teens and women    2.6 mcg
Breastfeeding teens and women    2.8 mcg
What foods provide vitamin B12?

Vitamin B12 is found naturally in a wide variety of animal foods and is added to some fortified foods. Plant foods have no vitamin B12 unless they are fortified. You can get recommended amounts of vitamin B12 by eating a variety of foods including the following:

    Beef liver and clams, which are the best sources of vitamin B12.
    Fish, meat, poultry, eggs, milk, and other dairy products, which also contain vitamin B12.
    Some breakfast cereals, nutritional yeasts and other food products that are fortified with vitamin B12. To find out if vitamin B12 has been added to a food product, check the product labels.

What kinds of vitamin B12 dietary supplements are available?

Vitamin B12 is found in almost all multivitamins. Dietary supplements that contain only vitamin B12, or vitamin B12 with nutrients such as folic acid and other B vitamins, are also available. Check the Supplement Facts label to determine the amount of vitamin B12 provided.

Vitamin B12 is also available in sublingual forms (which are dissolved under the tongue). There is no evidence that sublingual forms are better absorbed than pills that are swallowed.

A prescription form of vitamin B12 can be administered as a shot. This is usually used to treat vitamin B12 deficiency. Vitamin B12 is also available as a prescription medication in nasal gel form (for use in the nose).
Am I getting enough vitamin B12?

Most people in the United States get enough vitamin B12 from the foods they eat. But some people have trouble absorbing vitamin B12 from food. As a result, vitamin B12 deficiency affects between 1.5% and 15% of the public. Your doctor can test your vitamin B12 level to see if you have a deficiency.

Certain groups may not get enough vitamin B12 or have trouble absorbing it:

    Many older adults, who do not have enough hydrochloric acid in their stomach to absorb the vitamin B12 naturally present in food. People over 50 should get most of their vitamin B12 from fortified foods or dietary supplements because, in most cases, their bodies can absorb vitamin B12 from these sources.
    People with pernicious anemia whose bodies do not make the intrinsic factor needed to absorb vitamin B12. Doctors usually treat pernicious anemia with vitamin B12 shots, although very high oral doses of vitamin B12 might also be effective.
    People who have had gastrointestinal surgery, such as weight loss surgery, or who have digestive disorders, such as celiac disease or Crohn's disease. These conditions can decrease the amount of vitamin B12 that the body can absorb.
    Some people who eat little or no animal foods such as vegetarians and vegans. Only animal foods have vitamin B12 naturally. When pregnant women and women who breastfeed their babies are strict vegetarians or vegans, their babies might also not get enough vitamin B12.

What happens if I don't get enough vitamin B12?

Vitamin B12 deficiency causes tiredness, weakness, constipation, loss of appetite, weight loss, and megaloblastic anemia. Nerve problems, such as numbness and tingling in the hands and feet, can also occur. Other symptoms of vitamin B12 deficiency include problems with balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue. Vitamin B12 deficiency can damage the nervous system even in people who don't have anemia, so it is important to treat a deficiency as soon as possible.

In infants, signs of a vitamin B12 deficiency include failure to thrive, problems with movement, delays in reaching the typical developmental milestones, and megaloblastic anemia.

Large amounts of folic acid can hide a vitamin B12 deficiency by correcting megaloblastic anemia, a hallmark of vitamin B12 deficiency. But folic acid does not correct the progressive damage to the nervous system that vitamin B12 deficiency also causes. For this reason, healthy adults should not get more than 1,000 mcg of folic acid a day.
What are some effects of vitamin B12 on health?

Scientists are studying vitamin B12 to understand how it affects health. Here are several examples of what this research has shown:

Heart disease
Vitamin B12 supplements (along with folic acid and vitamin B6) do not reduce the risk of getting heart disease. Scientists had thought that these vitamins might be helpful because they reduce blood levels of homocysteine, a compound linked to an increased risk of having a heart attack or stroke.

Dementia
As they get older, some people develop dementia. These people often have high levels of homocysteine in the blood. Vitamin B12 (with folic acid and vitamin B6) can lower homocysteine levels, but scientists don't know yet whether these vitamins actually help prevent or treat dementia.

Energy and athletic performance
Advertisements often promote vitamin B12 supplements as a way to increase energy or endurance. Except in people with a vitamin B12 deficiency, no evidence shows that vitamin B12 supplements increase energy or improve athletic performance.
Can vitamin B12 be harmful?

Vitamin B12 has not been shown to cause any harm.
Are there any interactions with vitamin B12 that I should know about?

Yes. Vitamin B12 can interact or interfere with medicines that you take, and in some cases, medicines can lower vitamin B12 levels in the body. Here are several examples of medicines that can interfere with the body's absorption or use of vitamin B12:

    Chloramphenicol (Chloromycetin®), an antibiotic that is used to treat certain infections.
    Proton pump inhibitors, such as omeprazole (Prilosec®) and lansoprazole (Prevacid®), that are used to treat acid reflux and peptic ulcer disease.
    Histamine H2 receptor antagonists, such as cimetidine (Tagamet®), famotidine (Pepcid®), and ranitidine (Zantac®), that are used to treat peptic ulcer disease.
    Metformin, a drug used to treat diabetes.

Tell your doctor, pharmacist, and other health care providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.
Vitamin B12 and healthful eating

People should get most of their nutrients from food, advises the federal government's Dietary Guidelines for Americans. Foods contain vitamins, minerals, dietary fiber and other substances that benefit health. Dietary supplements might help in some situations to increase the intake of a specific vitamin or mineral. For more information on building a healthy diet, refer to the Dietary Guidelines for Americansexternal link icon and the U.S. Department of Agriculture's food guidance system, ChooseMyPlateexternal link icon.

Vitamin C, also known as ascorbic acid, is a water-soluble nutrient found in some foods. In the body, it acts as an antioxidant, helping to protect cells from the damage caused by free radicals. Free radicals are compounds formed when our bodies convert the food we eat into energy. People are also exposed to free radicals in the environment from cigarette smoke, air pollution, and ultraviolet light from the sun.

The body also needs vitamin C to make collagen, a protein required to help wounds heal. In addition, vitamin C improves the absorption of iron from plant-based foods and helps the immune system work properly to protect the body from disease.
Table of Contents

    What is vitamin C and what does it do?
    How much vitamin C do I need?
    What foods provide vitamin C?
    What kinds of vitamin C dietary supplements are available?
    Am I getting enough vitamin C?
    What happens if I don't get enough vitamin C?
    What are some effects of vitamin C on health?
    Can vitamin C be harmful?
    Are there any interactions with vitamin C that I should know about?
    Vitamin C and healthful eating
    Where can I find out more about vitamin C?
    Disclaimer

How much vitamin C do I need?

The amount of vitamin C you need each day depends on your age. Average daily recommended amounts for different ages are listed below in milligrams (mg).
Life Stage     Recommended Amount
Birth to 6 months    40 mg
Infants 7–12 months    50 mg
Children 1–3 years    15 mg
Children 4–8 years    25 mg
Children 9–13 years    45 mg
Teens 14–18 years (boys)    75 mg
Teens 14–18 years (girls)    65 mg
Adults (men)    90 mg
Adults (women)    75 mg
Pregnant teens    80 mg
Pregnant women    85 mg
Breastfeeding teens    115 mg
Breastfeeding women    120 mg

If you smoke, add 35 mg to the above values to calculate your total daily recommended amount.
What foods provide vitamin C?

Fruits and vegetables are the best sources of vitamin C. You can get recommended amounts of vitamin C by eating a variety of foods including the following:

    Citrus fruits (such as oranges and grapefruit) and their juices, as well as red and green pepper and kiwifruit, which have a lot of vitamin C.
    Other fruits and vegetables—such as broccoli, strawberries, cantaloupe, baked potatoes, and tomatoes—which also have vitamin C.
    Some foods and beverages that are fortified with vitamin C. To find out if vitamin C has been added to a food product, check the product labels.

The vitamin C content of food may be reduced by prolonged storage and by cooking. Steaming or microwaving may lessen cooking losses. Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are usually eaten raw.
What kinds of vitamin C dietary supplements are available?

Most multivitamins have vitamin C. Vitamin C is also available alone as a dietary supplement or in combination with other nutrients. The vitamin C in dietary supplements is usually in the form of ascorbic acid, but some supplements have other forms, such as sodium ascorbate, calcium ascorbate, other mineral ascorbates, and ascorbic acid with bioflavonoids. Research has not shown that any form of vitamin C is better than the other forms.
Am I getting enough vitamin C?

Most people in the United States get enough vitamin C from foods and beverages. However, certain groups of people are more likely than others to have trouble getting enough vitamin C:

    People who smoke and those who are exposed to secondhand smoke, in part because smoke increases the amount of vitamin C that the body needs to repair damage caused by free radicals. People who smoke need 35 mg more vitamin C per day than nonsmokers.
    Infants who are fed evaporated or boiled cow's milk, because cow's milk has very little vitamin C and heat can destroy vitamin C. Cow's milk is not recommended for infants under 1 year of age. Breast milk and infant formula have adequate amounts of vitamin C.
    People who eat a very limited variety of food.
    People with certain medical conditions such as severe malabsorption, some types of cancer, and kidney disease requiring hemodialysis.

What happens if I don't get enough vitamin C?

Vitamin C deficiency is rare in the United States and Canada. People who get little or no vitamin C (below about 10 mg per day) for many weeks can get scurvy. Scurvy causes fatigue, inflammation of the gums, small red or purple spots on the skin, joint pain, poor wound healing, and corkscrew hairs. Additional signs of scurvy include depression as well as swollen, bleeding gums and loosening or loss of teeth. People with scurvy can also develop anemia. Scurvy is fatal if it is not treated.
What are some effects of vitamin C on health?

Scientists are studying vitamin C to understand how it affects health. Here are several examples of what this research has shown.

Cancer prevention and treatment
People with high intakes of vitamin C from fruits and vegetables might have a lower risk of getting many types of cancer, such as lung, breast, and colon cancer. However, taking vitamin C supplements, with or without other antioxidants, doesn't seem to protect people from getting cancer.

It is not clear whether taking high doses of vitamin C is helpful as a treatment for cancer. Vitamin C's effects appear to depend on how it is administered to the patient. Oral doses of vitamin C can't raise blood levels of vitamin C nearly as high as intravenous doses given through injections. A few studies in animals and test tubes indicate that very high blood levels of vitamin C might shrink tumors. But more research is needed to determine whether high-dose intravenous vitamin C helps treat cancer in people.

Vitamin C dietary supplements and other antioxidants might interact with chemotherapy and radiation therapy for cancer. People being treated for cancer should talk with their oncologist before taking vitamin C or other antioxidant supplements, especially in high doses.

Cardiovascular disease
People who eat lots of fruits and vegetables seem to have a lower risk of cardiovascular disease. Researchers believe that the antioxidant content of these foods might be partly responsible for this association because oxidative damage is a major cause of cardiovascular disease. However, scientists aren't sure whether vitamin C itself, either from food or supplements, helps protect people from cardiovascular disease. It is also not clear whether vitamin C helps prevent cardiovascular disease from getting worse in people who already have it.

Age-related macular degeneration (AMD) and cataracts
AMD and cataracts are two of the leading causes of vision loss in older people. Researchers do not believe that vitamin C and other antioxidants affect the risk of getting AMD. However, research suggests that vitamin C combined with other nutrients might help keep early AMD from worsening into advanced AMD.

In a large study, older people with AMD who took a daily dietary supplement with 500 mg vitamin C, 80 mg zinc, 400 IU vitamin E, 15 mg beta-carotene, and 2 mg copper for about 6 years had a lower chance of developing advanced AMD. They also had less vision loss than those who did not take the dietary supplement.

More research is needed before doctors can recommend dietary supplements containing vitamin C for patients with AMD. However, people who have or are developing the disease might want to talk with their doctor about taking dietary supplements.

The relationship between vitamin C and cataract formation is unclear. Some studies show that people who get more vitamin C from foods have a lower risk of getting cataracts. But further research is needed to clarify this association and to determine whether vitamin C supplements affect the risk of getting cataracts.

The common cold
Although vitamin C has long been a popular remedy for the common cold, research shows that for most people, vitamin C supplements do not reduce the risk of getting the common cold. However, people who take vitamin C supplements regularly might have slightly shorter colds or somewhat milder symptoms when they do have a cold. Using vitamin C supplements after cold symptoms start does not appear to be helpful.
Can vitamin C be harmful?

Taking too much vitamin C can cause diarrhea, nausea, and stomach cramps. In people with a condition called hemochromatosis, which causes the body to store too much iron, high doses of vitamin C could worsen iron overload and damage body tissues.

The safe upper limits for vitamin C are listed below:
Life Stage     Upper Safe Limit
Birth to 12 months    Not established
Children 1–3 years    400 mg
Children 4–8 years    650 mg
Children 9–13 years    1,200 mg
Teens 14–18 years    1,800 mg
Adults    2,000 mg
Are there any interactions with vitamin C that I should know about?

Vitamin C dietary supplements can interact or interfere with medicines that you take. Here are several examples:

    Vitamin C dietary supplements might interact with cancer treatments, such as chemotherapy and radiation therapy. It is not clear whether vitamin C might have the unwanted effect of protecting tumor cells from cancer treatments or whether it might help protect normal tissues from getting damaged. If you are being treated for cancer, check with your health care provider before taking vitamin C or other antioxidant supplements, especially in high doses.
    In one study, vitamin C plus other antioxidants (such as vitamin E, selenium, and beta-carotene) reduced the heart-protective effects of two drugs taken in combination (a statin and niacin) to control blood-cholesterol levels. It is not known whether this interaction also occurs with other statins. Health care providers should monitor lipid levels in people taking both statins and antioxidant supplements.

Tell your doctor, pharmacist, and other health care providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.
Vitamin C and healthful eating

People should get most of their nutrients from food, advises the federal government's Dietary Guidelines for Americans. Foods contain vitamins, minerals, dietary fiber and other substances that benefit health. Dietary supplements might help in some situations to increase the intake of a specific vitamin or mineral. For more information on building a healthy diet, refer to the Dietary Guidelines for Americansexternal link icon and the U.S. Department of Agriculture's food guidance system, ChooseMyPlateexternal link icon