Question

Since vitamin d can be naturally produced by the skin, it is wise to not rely solely on vitamin supplements.

Answer 1

1. True in most cases
2. However exposure to sunlight (UVB) is variable everywhere and depends on nearness to equator, longitude, pigmentation-melanin and time spent in sunlight.
3. Some might not get adequate exposure due to above contributing factors.
4. Also Vit D has important roles in modulating innate and adaptive immune response and in autoimmunity.
5. In such cases, supplementation is essential.