Vitamin B-12 & Nutrition: A Primer for Vegetarians

This article is oriented towards Vegetarians and is one of a series on vitamins and minerals essential to maintaining optimal health.

What It Is

Vitamin B12 is an essential water-soluble vitamin that is critical for the normal functioning of the brain and nervous system and for the formation of blood. It is one of eight B vitamins and is frequently found in combination with the other B vitamins as part of a B-complex formula. Vitamin B12 helps maintain healthy nerve cells and red blood cells. It is normally involved in the metabolism of every cell of the body and is needed to make DNA, affecting not only DNA synthesis and regulation, but also fatty acid synthesis and energy production. The human body stores several years’ worth of vitamin B12 so a nutritional deficiency of this vitamin is very uncommon.  However, since B12 is usually found in foods not typically part of a vegetarian’s diet, such as fish, shellfish, meat, and dairy products, vegetarians have a challenge to ensure that they meet their daily allowance for B-12.

Why You Need It

For most individuals, a deficiency in B12 might occur because of an inability to absorb vitamin B12 from food. Strict vegetarians can also experience a deficiency due specifically to their avoidance of animal-based foods.  A deficiency in vitamin B-12 can be quite serious and could potentially cause severe and irreversible damage, especially to the brain and nervous system. At only slightly lower than normal levels, a person with a vitamin B12 deficiency may experience a host of symptoms ranging from poor memory, weakness, constipation, weight loss and fatigue to depression, anemia, mania, difficulty in maintaining balance, soreness of the mouth or tongue, and even psychosis. Further, a vitamin B-12 deficiency can lead to neurological changes such as numbness and tingling in the hands and feet. (Because many of these symptoms are very general and can result from a variety of medical conditions other than a vitamin B12 deficiency, it is very important to have a physician evaluate these symptoms rather than relying upon self-diagnosis.)

Where It’s Found

The bad news for vegetarians is that plants do not supply us with B-12. In fact, the only reliable unfortified sources of vitamin B12 are meat, dairy products and eggs. And while there has been much research into suggesting plant food sources of B12, such as  fermented soya products, seaweeds and algae, analysis of these products has concluded that they contain no significant form of B12 after all. (Compounds called B12 analogues are found in these products but they cannot be utilized to meet dietary needs.) The good news is that vitamin B12 can be found in vegetarian-friendly sources such as fortified breakfast cereals, fortified oatmeal, certain soy products and even some energy bars.

Special Considerations for Vegetarians

While lacto-ovo vegetarians typically get enough B-12 through their consumption of dairy products, vegans need to take special care. The Vegan Society, the Vegetarian Resource Group, and the Physicians Committee for Responsible Medicine all recommend that vegans consistently eat foods fortified with B-12 or regularly take a B-12 supplement such as those readily found in Vegetarian Vitamins.