Causes of vitamin deficiency

Vitamin deficiency rarely has a single cause - it usually grows out of what we eat, how well the gut absorbs, and what stage of life we are in.

Dietary causes. The commonest root in India is a monotonous diet: mostly rice or wheat with little dal, vegetables, fruit, dairy or eggs. Each missing food group removes specific vitamins - no dairy and eggs means poor B12, little fruit and raw vegetables means low C, few green vegetables and legumes means low folate, and minimal sun-exposed lifestyle plus no fortified food means low D. Highly polished grains and overcooking vegetables (vitamin C and folate are heat-sensitive) strip vitamins even from a decent plate.

Absorption problems. Coeliac disease, Crohn's disease, chronic diarrhoea, gastric or bariatric surgery, chronic liver and kidney disease all reduce uptake of multiple vitamins at once. Fat-soluble vitamins (A, D, E, K) need dietary fat and a healthy gut and liver to absorb at all.

Medicines and habits. Metformin lowers B12; long-term antacids do the same; some anti-epileptics deplete folate and D; isoniazid (TB treatment) depletes B6. Heavy alcohol damages absorption, storage and intake together. Smoking raises vitamin C needs.

Life stages with higher needs. Pregnancy and breastfeeding (folate, D, B12, iron-related), growing children, adolescents, and the elderly - whose skin makes less vitamin D and whose stomachs absorb less B12.

The Indian paradox: despite abundant sunlight, vitamin D deficiency is extremely common because of indoor lifestyles, covered clothing, darker skin needing more sun, and air pollution filtering UVB.

Ayurvedic view (interpretive): classical texts describe under-nourishment states as dhatu kshaya with weakened agni (digestive capacity) - a traditional interpretive framework that roughly parallels modern ideas of poor intake plus poor assimilation. Evidence for this mapping is limited; it complements, never replaces, nutritional assessment and testing.

Remember: monotonous diet plus poor absorption plus life-stage needs is the usual recipe. If you are on metformin, antacids or TB medicines, or have gut disease, ask your doctor which vitamins to monitor.