The Economist declared 2019 “the year of the vegan“. Globally, more people are adopting the vegan lifestyle today than ever before. Vegan restaurants are opening up in every geography. Supermarkets are improving their selection of vegan processed food. Don’t be surprised if a plant-based meat shop opens up next to your neighborhood KFC.
The reason for going vegan may be health related, after all, there is documented evidence linking reduction or exclusion of animal foods to lower risk of lifestyle diseases. Or the reasons may be ethical and environmental. In the latter case, knowledge about the nutritional aspects of such a choice might be lacking. Although well-planned vegan diets are considered appropriate for all stages of life, including infancy and pregnancy, it requires food fortified with Vitamin B12, Vitamin D, Calcium and certain useful Fatty Acids which are naturally deficient in plant based diets.
Vitamin B12, also called Cobalamin, is a water soluble vitamin important for making DNA, myelin sheaths (structural component of a nerve cell), neurotransmitters and matured blood cells. Recommended Daily Intake (RDI) of Vit B12 for adults and pregnant women is 2.4 and 2.6 micrograms respectively. A common misconception among vegetarians is that the presence of dairy products and eggs in their diet is enough to take care of their Vit B12 requirements. It’s body stores lasts for several years and its deficiency develops slowly. However, the combination of malabsorption and inadequate dietary intake will hasten its deficiency. The only substantial source is animal meat. The prevalence of vitamin B12 deficiency (<200 pg/ml) is at least 47% in Indian population. If B12 levels of 200 – 300 pg/ml are considered as borderline deficient, then up to 74% of the Indian population would be potentially deficient.
Clinical manifestations of Vit B12 deficiency can be broadly divided into neuropsychiatric (like myelosis, cognitive disorders, depression and dementia) and hematological (like megaloblastic anemia). Neurological symptoms are the first to appear. Typically a new patient comes with complains of pins and needles sensation in the foot sole and along the legs. The diagnosis is based on clinical symptoms and blood investigations, but no gold standard test exists at present.
At risk population for Vit B12 deficiency:
- Vegan/Vegetarian diet.
- Elderly (Age > 51 years).
- Pregnant women, lactating mothers and their infants.
- Patients who have had weight loss surgery.
- Patients taking proton pump inhibitors (PPIs) like Pantoprazole (popular among the elderly as Gas ki Dawai a.k.a. Medication for Dyspepsia) or diabetics taking Metformin.
- Patients with Gastrointestinal conditions.
- Diet – Inclusion of more dairy products and eggs in a vegetarian diet. Shiitake mushroom is an excellent source as well. As mentioned above, a vegan/vegetarian diet alone isn’t enough to meet daily requirements.
- Food Fortification – Food fortified with Vit B12, like nutritional yeast flakes and breakfast cereals. But considering the magnitude of deficiency in the general population wheat flour fortification is being looked at with great interest. Presently, there aren’t enough intervention trials on the effect of different fortification levels of flour in different populations. But this will be a huge opportunity for wheat flour companies in India going forward if they can do what Tatas did with Tata Salt Plus to combat nutritional iron deficiency in India.
- Oral supplementation – Vit B12 pills are available over the counter in varying doses. A standard multivitamin delivers 6 micrograms of Vit B12, more than enough to cover the average body’s daily needs. But some studies have shown that using multivitamins can be inefficient and counterproductive for the supplementation of Vit B12 as Vit C and copper in such pills can form inactive by-products with Vit B12.