Why Vitamin D Deficiency Is Increasing in India?

Vitamin D deficiency has emerged as a major public health challenge in India, affecting nearly half the population despite the country’s tropical climate and year-round sunshine. Recent studies, including a comprehensive report by ICRIER-ANVKA (2025), reveal that about one in five Indians suffers from severe vitamin D deficiency, with children, pregnant women, and older adults being the most vulnerable groups.^[1]

This deficiency is not only linked to skeletal disorders like rickets and osteomalacia (softening of the bones), but some studies have shown a potential correlation between vitamin D deficiency and cardiovascular diseases, type 2 diabetes, autoimmune diseases and certain cancers.^[2]

The rising prevalence underscores the urgent need for awareness, routine screening, and targeted interventions to combat this growing health crisis.

Why is Vitamin D Deficiency Increasing in India?

To understand this crisis, we must look at five key factors contributing to low vitamin D levels: lifestyle, biological, environmental, dietary, and medical factors.

1. Indoor lifestyles & limited sun exposure

Modern urban lifestyles in India mean most people spend most of their time indoors, whether at work, school, or home. Office jobs, long commutes, and the use of air conditioning further reduce direct sun exposure.

Glass windows in buildings and vehicles also significantly filter or block the UVB rays needed for vitamin D synthesis, compounding the problem.

The Metropolis study (2025) highlights that urban populations are more affected than their rural counterparts due to their indoor-centric lifestyles and limited exposure to sunlight. This trend is particularly pronounced in densely populated cities like Delhi, where the risks are even more pronounced.

2. Skin pigmentation & clothing / cultural norms

Indians typically have darker skin, which requires more sun exposure to produce the same amount of vitamin D as lighter skin. Cultural norms, such as wearing full clothing for modesty or religious reasons, further limit exposure of skin to sunlight, especially among women and children.

The ICRIER-ANVKA report (2025) found that cultural and skin-tone factors, such as darker skin tones and clothing practices, reduce sun absorption, exacerbating the deficiency. People with lighter skin may require less time in the sun to produce the same amount of vitamin D as those with darker skin tones.^[3]

3. Air pollution & geographic factors

India’s high levels of air pollution, particularly in major cities, block UVB rays, reducing the skin’s ability to synthesise vitamin D. Seasonal changes, such as the monsoon and winter months, also limit sun exposure, increasing the risk of deficiency during these periods. The prevalence of vitamin D deficiency is highest in the country's eastern region, where pollution levels are particularly high.^[4]

4. Poor dietary intake & lack of fortified foods

Indian diets are often low in foods naturally rich in vitamin D, such as fatty fish and eggs. Fortified foods are not widely available, and vegetarian diets, which are common, rarely include these sources. This dietary gap makes it difficult for many Indians to maintain adequate vitamin D levels solely through diet.

5. Malabsorption, obesity & medical conditions

Certain medical conditions, such as celiac disease, inflammatory bowel disease, and obesity, can impair vitamin D absorption or metabolism.^[5] These conditions are more prevalent in certain populations, increasing their risk of deficiency. 

Conclusion

Despite rising vitamin D deficiency in India, the solution remains within our reach. Addressing this issue requires public awareness, routine screening, nutritional interventions, and lifestyle changes to ensure adequate vitamin D levels for better health outcomes. The ICRIER-ANVKA report (2025) and other studies highlight the urgent need for a national strategy, including food fortification, public awareness campaigns, and affordable testing and supplementation, to combat this silent epidemic and improve public health in India.