Vitamin B12 and Vegetarian Athletes

Many people know that vitamins and minerals are necessary for basic functioning.  There are two basic types of vitamins, fat soluble and water soluble.  The fat soluble vitamins are A, D, E, and K.  the rest are water soluble.  It is possible to overdose on fat soluble.  But if someone ingests too much of the water soluble vitamins, the extras are dumped in the urine.  However, B12 doesn’t follow the same rules as other water soluble vitamins.  It can actually be stored in the liver with supplies that will last someone years.  One of the most common deficiencies in people that experience is actually a water soluble vitamin, Vitamin B12.  People most at risk are  athletes who are limiting calories or have specialized, consistent or restricted eating plans (avoiding meat, diary, and/or eggs).

Vitamin B12 plays an extremely important role in the body.  B12, along with the rest of the B vitamins, is a  ‘micronutrient’ and is used to convert proteins and carbohydrates into energy.  B vitamins are also used for cell repair and production.    Vitamin B12 specificially plays a role in red blood cell production and maintenance of the central nervous system.  A study at Oregon State University showed that even a small deficiency in B vitamins decreased the athletes ability to perform at high intensities and also delayed muscle recovery/repair after workouts.  With the knowledge of what B vitamins do for the body, its easy to see why a slight lack of these in the diet can result in drastic outcomes for athletes trying to perform well for race day, or even recover fast enough for their next working later in the day or tomorrow.

Since a vegetarian or vegan diets tend to limit or completely remove animal products, the natural sources for vitamin B12 are not going to be consumed by the individual.  These sources include eggs, meat, poultry, shellfish, milk, and milk products.   However, many fortified cereals contain all of, or most of the recommended daily intake of B12.  Additionally, if you buy a milk substitute, most of brands of almond, rice, soy milk are fortified with 50% of the recommended intake of B12 per 8 oz. serving.  With foods being fortified with B12, it is much easier than it was several years ago to consume enough each day.  However, many of the new “all natural” or “organic” cereals are not fortified.  So people that tend to buy these types of cereals are at a greater risk of a deficiency.

The daily recommended intake for B12 is about 2.4 mcg.  However, this number isn’t consistent across the board of experts.  A lot depends on the person’s ability to absorb the vitamin, their activity level, and many other factors.  Below are some common foods that contain higher levels of B12:


Sources of Vitamin B12
Food[58] µg vitamin B12/100g
beef liver 83.1
turkey giblets 33.2
pork liver sausage 20.1
Raw Pacific oysters 16.0
Cooked Alaska king crab 11.5
Raw clams 11.3
Simmered chicken giblets 9.4
Cheese 3.3
Beef (uncooked sirloin) 1.15
Egg (raw, whole chicken’s egg) 0.89
Whole cow’s milk 0.45


As mentioned above, only animal sources naturally contain B12.  So people eating a restricted diet should closely monitor their B12 intake.  But, even if their daily intake isn’t enough, the results won’t begin to show up for several years since B12 is stored in the liver.  Vitamin B12 deficiency is characterized by anemia, fatigue, weakness, constipation, loss of appetite, and weight loss. Neurological changes, such as numbness and tingling in the hands and feet, can also occur. Additional symptoms of vitamin B12 deficiency include difficulty maintaining balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue. The neurological symptoms of vitamin B12 deficiency can occur without anemia, so early diagnosis and intervention is important to avoid irreversible damage.  Some of the neurological changes caused from B12 deficiency can be irreversible.

For myself, after being vegan for nearly a year, I decided that it wasn’t a good thing for me to continue doing.  Personally, I feel like I’m cheating if I take multivitamins to replace nutrients (although I do take a multivitamin occasionally).  I decided to start including eggs and cheese again, and meat about once a week.  With the fortified cereals that I eat, I am getting enough B12.  I don’t drink milk, but rather make my own soy milk, so the soy milk I consume doesn’t have B12 in it either.  If someone is unwilling to change their diet to include animal sources of B12, another really good source of B12 (and all the B vitamins) is something called nutritional yeast.  Just a 1/4 cup of it contains 150% of the RDA of B12 for the day and 9 grams of protein.  It has a cheesy flavor to it, and if used correctly can be a tasty alternative to cheese on vegetables, in casseroles, and many other dishes or soups.


For more information on vegetarian diets and protein, click here.

For more information on vegetarian diets and iron, click here.