Why vegetarians should worry about vitamin B12 intake
The levels of vitamin B12 found in non-vegetarian sources like salmon and liver far outstrip the levels found in vegetarian foods like milk and cheese
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Have you had your vitamin B12 levels checked recently? A 37-year-old homemaker in Delhi had been suffering from mood swings for over six months before her family and general physician suggested she consult a psychiatrist. The psychiatrist ordered a battery of blood tests for hormonal imbalances and nutritional deficiencies. The woman’s blood report was normal apart from vitamin B12 levels—they were very low, at 70 pg/ml (below 250 pg/ml is defined as deficient). The psychiatrist recommended 10 vitamin B12 injections over 20 days combined with daily vitamin B12 tablets.
The why of vitamin B12
Vitamin B12 is profoundly important for health. Adequate stores of the vitamin help our nerve and blood cells to function properly; this vitamin is also needed for the manufacture of DNA strands in the body. If left untreated, vitamin B12 deficiency can lead to permanent nerve damage. Sanjay Chugh, a psychiatrist who practises in New Delhi, says: “Vitamin B12 deficiency is rampant in India (among men and women). The deficiency is so common that it’s the first thing I recommend for patients regardless of their psychiatric symptoms. And often when vitamin B12 deficiency is found, simple supplementation of vitamin B12 is enough to clear the symptoms such as mood swings and crying bouts.” Vitamin B12 injections are recommended when the deficiency diagnosed is severe and vitamin B12 levels have to be brought back to normal quickly. Once the levels have normalized, then vitamin B12 can be taken orally like any other vitamin supplement.
One reason why vitamin B12 deficiency is particularly common in India is that a large number of people here are vegetarians.
Vitamin B12 is a water-soluble vitamin found in meat, fish, dairy and vegetarian fortified foods. And while the best sources of vitamin B12 include milk, yogurt, cheese, eggs, meat, and chicken, the levels of vitamin B12 found in non-vegetarian sources like salmon and liver far outstrip the levels of vitamin B12 found in vegetarian foods like milk and cheese. Besides, vegetarian fortified foods like fortified soya or fortified breakfast cereal are not commonly consumed in India.
A 2012 study on vitamin B12 levels in obese women of South Asian origin living in Auckland, New Zealand, found that 24% of the vegetarians and 9% of the non-vegetarians were vitamin B12 deficient. The study was published in the journal Nutrition. A review of 18 such studies published in Nutrition Reviews in February examined how common vitamin B12 deficiency is among vegetarians and the authors, R. Pawlak and colleagues from East Carolina University, US, concluded that “vegetarians develop B12 depletion or deficiency regardless of demographic characteristics, place of residency, age, or type of vegetarian diet. Vegetarians should thus take preventive measures to ensure adequate intake of this vitamin, including regular consumption of supplements containing B12”.
A tough one
Taken through food, vitamin B12 needs to be separated from the protein by the acids and enzymes in the stomach into its active form.
But the stomach acid secretion goes down among 30% of people over the age of 50, so they can no longer unlock adequate amounts of vitamin B12 from the foods they eat. This keeps levels of the vitamin low in the bloodstream. The only way to replenish vitamin B12 stores then is through oral supplementation or injections. Oral tablets have vitamin B12 in its free form and don’t need stomach acids to aid absorption.
Dominic Benjamin, consultant geriatrician, Bangalore Baptist Hospital, says people over the age of 50 should be particularly watchful about B12 deficiency. In an email interview, he wrote: “In my practice, which is for older people, significant proportion of my patients show symptoms of tiredness, tingling and numbness in their feet or breathlessness and while a majority of them have iron-deficiency anaemia, I find that 25-30% have vitamin B12 deficiency.”
The symptoms of vitamin B12 deficiency, regardless of the age at which it occurs, include skin pallor, shortness of breath, palpitation, nerve pain, weakness, balance problems, vision loss, and a host of psychiatric symptoms, including personality changes, hallucinations, paranoia, depression and violent behaviour.
Some people may have some of the symptoms but no single symptom characterizes the deficiency more than the intermittent sensation of tingling in the hands and feet.
Dr Chugh says: “I am stunned how few psychiatrists test for vitamin B12 given how common this deficiency is and how easy it is to correct.” All it needs is a blood test.
Sujata Kelkar Shetty, PhD, writes on public health issues and is a research scientist trained at the National Institutes of Health in Bethesda, US.