What is Vitamin B12
Vitamin B12 is a water soluble B group vitamin that is essential for health. There is an atom of cobalt in every molecule of vitamin B12, which is why it is also known as cobalamin. Vitamin B12 has a range of functions within the body including red blood cell synthesis, neurological function, and DNA synthesis. It is also involved with hormone, protein, and fat metabolism (NIH, 2011).
Where Does Vitamin B12 Come From?
Vitamin B12 is generally only found in foods from animal sources. This includes fish, meat, eggs, and dairy products. Because it is stored in the liver, liver meats are a great source of this vitamin. Vitamin B12 does not naturally occur in plant foods, though processed foods such as cereals can be fortified with vitamin B12.
Vitamin B12 Benefits
Because of the role of vitamin B12 in protein and fat metabolism, as well as its involvement in red blood cell synthesis, it is absolutely vital for exercise performance. Vitamin B12 deficiency causes a form of anaemia (megaloblastic anaemia) which results in fatigue, weakness, and of course, poor endurance (NIH, 2011). This, in addition to all the other functions of vitamin B12, it is essential to ensure your levels are topped up.
Vitamin B12 Negatives and Side Effects
Taking high level of vitamin B12, above what your body needs is unlikely to result in improved exercise performance. It is therefore not considered an ergogenic aid, and does not have any direct exercise boosting properties.
Vitamin B12 is an extremely safe vitamin. According to the Institute of Medicine (1998), it has very low toxicity and there are no known adverse effects from consuming B12 from either food or supplements. In a long term study, it was shown that supplementing with 1 mg vitamin B12 for over five years resulted in no serious adverse health effects Lonn et al (2006).
Vitamin B12 Recommended Dose and Ingredient Timing
The recommended intake set by the Institute of Medicine (1998) is 2.4 micrograms per day. This is generally easily obtainable by most healthy people. Bodybuilders in particular, should have no problems meeting these levels because of the large amount of animal products they tend to consume. However, certain groups of people may find it difficult to reach adequate levels of vitamin B12 intake. Very strict vegetarians and vegans may not be consuming adequate vitamin B12, as this vitamin only naturally occurs in animal products. In this case, it is necessary to ensure that vitamin B12 is obtained through supplements.
Certain drugs also reduce the absorption of vitamin B12. These include drugs to treat diabetes, gastro reflux, and certain antibiotics.
Intrinsic factor, secreted from the stomach, is needed for vitamin B12 to be absorbed. It is therefore best to take vitamin B12 at meals or with food.
Vitamin B12 Supplements
Stand-alone vitamin B12 supplements are readily available. Quite often, these are made from microbiological sources, and are therefore vegetarian/vegan friendly. Vitamin B12 can also be found in multivitamin supplements, pre workout supplements, and a large variety of protein powders.
Stacking Vitamin B12
Vitamin B12, as with other vitamins can be stacked with pretty much anything, as evident by how widely occurring this vitamin is.
Institute of Medicine. Food and Nutrition Board (1998), Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline, National Academy Press, Washington, DC
Lonn et al (2006), Homocysteine lowering with folic acid and B vitamins in vascular disease. N Engl J Med, 354: 1567-1577
NIH (2011), Dietary Supplement Fact Sheet: Vitamin B12. Office of Dietary Supplements, National Institute of Health