Vitamin D is a fat-soluble vitamin that plays several crucial roles in the body. It helps the body absorb calcium, which is fundamental for maintaining healthy bones¹. Without sufficient vitamin D, bones can become thin, brittle, or misshapen, leading to conditions like osteoporosis in adults and rickets in children²³.

The body produces vitamin D naturally when the skin is exposed to sunlight. However, because of sun exposure risks, dietary sources and supplements become important, especially during months with limited sunlight exposure⁴⁵. Natural food sources of vitamin D are relatively scarce but include fatty fish such as salmon and mackerel, beef liver, cheese, egg yolks, and certain mushrooms⁶⁷. Many foods like milk, cereals, and orange juice are fortified with vitamin D to help people meet their daily needs⁸.

Vitamin D comes in two main forms in supplements: D2 (ergocalciferol) and D3 (cholecalciferol). D3 is generally more effective in raising and maintaining vitamin D levels in the blood⁹¹⁰.

While vitamin D is essential for health, excessive amounts can lead to toxicity, resulting in nausea, vomiting, weakness, and more serious conditions such as kidney damage¹¹.

Footnotes

1. MedlinePlus Medical Encyclopedia ↩

2. MedlinePlus Medical Encyclopedia ↩

3. NHS ↩

4. Office of Dietary Supplements - Vitamin D ↩

5. NHS ↩

6. Harvard Nutrition Source ↩

7. Mayo Clinic ↩

8. Office of Dietary Supplements - Vitamin D ↩

9. Harvard Nutrition Source ↩

10. Office of Dietary Supplements - Vitamin D ↩

11. MedlinePlus Medical Encyclopedia ↩