During the past few decades, vegetarian diets that limit intake of animal products have been more popular. The reasons behind the embracement of such diets could be due to religious, philosophical, and especially health reasons. Vegetarians are generally healthy, well-nourished and prevented from co-morbidities such as mal-absorption, clogged arteries or protein calorie malnutrition, to name a few. Indians, in particular, have a low vitamin B12 due to their lacto-vegetarianism, social custom, religious reasons and lack of meat in the nutrition of the omnivores. The vitamin B12 content of serum in vegetarians is significantly lower than that of non-vegetarians, regardless of their class of vegetarianism, and often these levels are below the normal values.
Vegetarianism is classified into four different categories. Lacto-vegetarian diets include dairy products, ovo-vegetarians eat eggs, lacto-ovo-vegetarians consume both dairy products and eggs and vegans have no animal products in their diet at all. Vitamin B12, found as cobalamin in foods of animal origin, is acquired from fish, meat in particular liver, chicken breast, poultry, milk products and eggs. It cannot be synthesized in humans; therefore inadequate intake of meat, in vegetarianism, is the most frequent type of vitamin B12 deficiency. Vegetarians must take Vitamin B12 supplements, because its active form is not found in plant foods except as a contaminant or through fortification.
Vitamin B12 deficiency is becoming a widespread hidden pandemic affecting the worldwide population; however people are unaware of this condition especially in regards to its relation to vegetarianism. Vitamin B12 is found only in microorganisms that naturally produce it such as ones of animal origin; hence individuals must maintain their vitamin B12 levels solely from their diet. Vegetables that are organically grown have a higher level of vitamin B12 because they have not been exposed to chemical fertilizers. Indian lacto-vegetarians that make up around half of India’s population have markedly lower vitamin B12 concentrations than the non-vegetarian Indians. This puts a great portion of the Indian population, living in India and abroad, at risk of developing vitamin B12 deficiency at one stage in their lives.
Indians throughout the world are at a high risk of developing cardiovascular diseases, which makes them an easy target for studies conducted on Vitamin B12 deficiency. Total vegetarians often manifest neuropsychiatric disorders due to the low stores of vitamin B12 in their liver. Low serum B12 levels have also been found in lacto-ovo-vegetarians who use dairy products and eggs, but no meat, fish, or poultry.
During pregnancy, the fetus’ supply of vitamin B12 is dependent on the mother. Vitamin B12 is actively transferred to the fetus across the placenta reaching twice the level of maternal serum. Vitamin B12 from the mother’s own stores is not transferred to the fetus; instead, B12 from the mother’s daily diet, or the supplements she takes during her pregnancy, cross the placenta to the fetus. Therefore, at birth, babies are born with a reserve of vitamin B12 and in a normal infant vitamin B12 store levels are around 25 to 50 μg, enough for the first 6 to 12 months of life. Thus, deficiency in vitamin B12 levels in these first few months of life can only occur in infants with maternal vitamin B12 deficiency, which is a strong indication of the mother’s vitamin B12 levels as well.
The longer a woman has been exposed to vegetarianism, the more likely it is that they will develop a low maternal serum and breast milk vitamin B12 concentrations as a mother, increasing the chances of a low vitamin B12 level in their infants. Maternal dietary deficiency results in a range of conditions in the infant. These include anemia, neurological signs and symptoms such as irritability, apathy, developmental retardation, ataxia, paresthesia, hyporeflexia, hypotonia, tremor, seizures, loss of acquired motor abilities, and even coma.
Deficiencies of the B vitamins, B9 folic acid, B6 pyridoxine and B12 cyanocobalamin, can lead to high homocysteine levels. Elevated circulating total homocysteine (tHcy) concentration, hyperhomocysteinemia, is a common risk factor for occlusive vascular diseases which can be modified through alteration in diet patterns. Along with this, it can also cause some neural tube and birth defects, poor pregnancy outcomes and neuro-cognitive performance, congenital heart defects, dementia and Alzheimer disease. Knowledge of these complications should encourage vegetarians to reverse their vitamin B12 deficiency by taking B12 supplements.
Dr Sarkaw Mohammad (Chiropractor)
Mobile: 021 100 7363
Hillcrest Spinal Centre
174 Cambridge Road, Hamilton