Vitamin D is an essential fat-soluble vitamin known for its crucial role in maintaining bone health by aiding in the absorption of calcium¹. It helps ensure proper bone formation and prevents conditions like osteoporosis in adults and rickets in children¹. Besides its bone health benefits, vitamin D is also involved in muscle function, immune response, and inflammation reduction²³.

The body primarily obtains vitamin D through exposure to sunlight, which triggers its synthesis in the skin². Due to varying levels of sunlight exposure, many people may not get enough vitamin D solely from sun exposure, especially during seasons with limited sunlight. Therefore, dietary intake and supplements play an important role in maintaining adequate vitamin D levels³.

Few foods naturally contain significant amounts of vitamin D. Fatty fish such as salmon, mackerel, and sardines are among the best dietary sources⁴. Other sources include beef liver, cheese, egg yolks, and mushrooms exposed to ultraviolet light⁴⁵. Many foods, including milk, cereals, and juices, are fortified to provide additional vitamin D².

Vitamin D supplements are available in two forms: D2 (ergocalciferol) and D3 (cholecalciferol). D3 is generally considered more effective at raising and maintaining vitamin D levels in the body³⁴.

While vitamin D is essential, excessive intake can lead to high calcium levels in the blood, potentially causing adverse effects such as kidney damage and confusion¹. It's important to balance vitamin D intake through sunlight, diet, and supplements to maintain optimal health.

Footnotes

1. MedlinePlus - Vitamin D ↩ ↩² ↩³

2. Better Health - Vitamin D ↩ ↩² ↩³

3. Harvard Nutrition Source - Vitamin D ↩ ↩² ↩³

4. Office of Dietary Supplements - Vitamin D ↩ ↩² ↩³

5. NCBI - Sources of Vitamin D ↩