The ICMR-NIN 2020 RDA for vitamin D for adults in India is 600 IU/day (15 µg). Despite abundant sunlight in India, widespread vitamin D deficiency persists. The PRIMARY epidemiological reason for this paradox is:
- A Indoor lifestyle, air pollution reducing UV-B penetration, and dark skin pigmentation requiring longer sun exposure ✓
- B Indian diet is deficient in calcium, blocking vitamin D activation
- C Cooking practices that destroy vitamin D in fortified foods
- D High calcium intake in dairy-consuming populations blocking vitamin D absorption
Correct answer: A. Indoor lifestyle, air pollution reducing UV-B penetration, and dark skin pigmentation requiring longer sun exposure
Explanation
Despite India's geographic latitude receiving adequate UV-B, vitamin D deficiency affects 70–90% of Indians due to a triad of factors: indoor-predominant lifestyle reducing sun exposure, particulate air pollution (especially in North India) significantly attenuating UV-B reaching the skin, and melanin-rich skin requiring 3–5 times longer sun exposure than fair skin to synthesise the same amount of vitamin D. Dietary sources of vitamin D are inherently scarce in traditional Indian diets. These factors collectively override geographic advantage.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.