By SUSAN CALLAHAN, Associate Editor and Featured Columnist
Let's get through the denials, first. If you are a vegan, chances are, you are not getting enough Vitamin B12. How high are the chances? Very high. A study from found that 86% of vegans are not getting enough B12 and 31% of vegetarians are also vitamin B12 deficient.
Vitamin B12, technically called cobalamin, is needed to produce red blood cells. It is a cofactor in amino acid and metabolic chemical pathways, and heavily involved in sustaining a healthy nervous system. Deficiency in Vitamin B12 renders the body unable to properly produce the myelin sheath, and as a result the nerve cells are not able to properly transmit signals.
This vitamin is found only in animal foods.
Scientists and doctors have not agreed on how much Vitamin B12 vegans or any of us, for that matter, need. However, having blood levels of Vitamin B12 below 300 pmol/L is associated with a significant risk of Vitamin B12 deficiency, according to a 2012 study from Oxford in the Journal of Internal Medicine led by Dr. A. David Smith and Dr. Helga Refsum.
Below this level, you often see symptoms of Vitamin B12 deficiency.
What Are the Symptoms of Vitamin B12 Deficiency?
Symptoms of a Vitamin B12 deficiency include
losing your balance
By the time you have these symptoms, you are severely deficient. See a doctor.
How Much Vitamin B12 Should Vegans Take?
One study from sheds some light on this issue. Scientists from the University of Sidney in Australia and The Chinese University of Hong Kong assembled 50 healthy vegetarians with blood Vitamin B12 levels below 150 . Recall that levels below 300pmol/L run a high risk of producing Vitamin B12 deficiency.
For 12 weeks, these 50 people were divided into tow groups that were given either 500 micrograms per day of a Vitamin B12 supplement or a placebo.
The 12 weeks of supplementation significantly changed the blood profiles of those who had taken the B12. They had higher blood levels of B12, as one would expect, with the levels almost tripling from 134 to 379 pmol/L.
Moreover, cardiovascular markers also improved. High homocysteine levels are associated with a higher risk of heart attacks and strokes. The Vitamin B12 supplementation lowered homocysteine levels from 16 to 11 micromol/L.
Finally, and perhaps most tellingly, the measurements of arterial blood flow increased. Brachial flow mediated dilation is a measure of . Brachial flow mediated dilation predicts the risk of cardiovascular attacks in the elderly. Other studies have found that brachial flow mediation also predicts your risk for cardiovascular disease better than other measures.
For example, a 2013 study from Chaim Sheba Medical Center and Tel Aviv University in Israel called this measure "the best independent predictor of long term Cardiovascular adverse events". In the Australian study, brachial mediated flow increased from 6.3% to 6.9% after Vitamin B12 supplementation.
Going vegan is a choice. But it's also a responsibility. You have to have your Vitamin B12 levels assessed regularly if you have adopted this way of eating. There's no getting around it.
And, you should strongly consider adding B12 supplements to diet. There is no toxic level of Vitamin B12, Harvard University's medical blog indicates, so, together with your doctor, you should experiment to find the optimal level of supplementation needed to raise your blood B12 levels to normal.