Vitamin B12 and a Vegan Diet


 
   

Sources of vitamin B12 in your diet 

Persons on a strict vegan diet cannot obtain enough vitamin B12 from their diet to satisfy their normal daily requirement. Thus standard foods for vegans such as fruits, vegetables, nuts or legumes do NOT contain a significant amount of the vitamin.  Vegans should be aware that even a mild deficiency of vitamin B12 can cause anemia, fatigue, depression, whilst prolonged deficiency can cause neurological conditions and has been associated with an increased incidence of Alzheimer's disease, multiple sclerosis and dementia. Many studies have shown vitamin B12 deficiency in persons on vegan and vegetarian diets.  Several studies have shown that prolonged maintenance of a vegan diet can also lead to subacute degradation of the spinal chord, optic neuritis, optic atrophy, dimness of sight and even blindness, a condition that may be worse in those who smoke. .

Vegan mothers who are vitamin B12 deficient can give birth to under-weight babies, who may already have signs of spinal chord damage. Following birth babies can fail to thrive and show developmental regression. In many cased the babies can become lethargic and lose their ability to use their muscles adequately. Some cannot sense properly and most have macrocytic anemia. In many cases, even the taking of vitamin B12 supplements by the mother cannot help the babies. Other studies have shown that babies born to vitamin B12 deficient mothers are more likely to be insulin resistant, a predisposing factor for the development of diabetes.

Vegans eventually end up with vitamin B12 deficiency and may present with various diseases associated with vitamin B12 deficiency, including motor defects (including trouble walking and unstable gait), numbness and tingling in the hands and feet, being easily fatigued, neurological conditions, subacute neuronal degeneration, poor vision and severe optic disease, confusion, incontinence plus other signs of VB12 deficiency including anorexia, swollen tongue, macrocytic anemia, jaundice, vomiting, abdominal pain.

Potential foods of dietary benefit to vegans that contain vitamin B12 are Cheeses (3.3 ug/100 gm serving of Swiss cheese), whey powder (2.5 ug/100 gm), milk (0.46 ug/cup), yogurt (0.53 ug/100 gm), yeast extract (Marmite - there is none in Vegemite). 

Topical Vitamin B12 

The topical form of vitamin B12 developed by Mentor and associates is a specially formulated preparation that is an easy to apply, needle-free delivery system to the skin. A once weekly application of a single dose of Topical vitamin B12 to the forearm and can supply adequate vitamin B12 even for those on vegan or vegetarian diets. In addition, the topical formulation is particularly suited to patients who may have gastro-intestinal problems, such as Crohn’s Disease and Ulcerative Colitis which often lead to vitamin B12 deficiency. 

Further Information on Dietary Requirements for vitamin B12

Further Information on the recommended daily allowance for vitamin B12 can be found at the following web-sites:

http://fnic.nal.usda.gov/dietary-guidance/dietary-reference-intakes/dri-tables

http://www.nhmrc.gov.au/guidelines/publications/n6

http://www.healthyeatingclub.com/info/books-phds/books/foodfacts/html/data/data2h.html

http://www.nal.usda.gov/

http://www.veganhealth.org/b12/apinfants

Publications on vitamin B12 deficiency in Vegans can be found here