Vitamin D(calciferol)

Vitamin D(calciferol)

Definition: Vitamin D(calciferol) is a fat-soluble vitamin that plays a crucial role in maintaining bone health, regulating calcium and phosphorus levels in the body, and supporting immune function. It exists in two primary forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

Importance of Vitamin D

• Bone Health: Vitamin D is essential for the absorption of calcium in the intestines, which is critical for the development and maintenance of strong bones. A deficiency can lead to conditions such as rickets in children and osteomalacia or osteoporosis in adults.
• Immune Function: It plays a role in modulating the immune system, helping the body defend against infections and reducing inflammation.
• Muscle Function: Adequate levels of vitamin D are important for muscle strength and function, which can help reduce the risk of falls, particularly in older adults.
• Chronic Disease Prevention: Research suggests that sufficient vitamin D levels may lower the risk of certain chronic diseases, including cardiovascular disease, diabetes, and some cancers.

Sources of Vitamin D

Vitamin D can be obtained from various sources:

• Sunlight: The skin synthesizes vitamin D when exposed to ultraviolet B (UVB) rays from sunlight. This is often considered the most significant source.
• Food: Dietary sources include fatty fish (such as salmon and mackerel), fish liver oils, fortified foods (like milk, orange juice, and cereals), egg yolks, and cheese.
• Supplements: Vitamin D supplements are available in both D2 and D3 forms and are often recommended for individuals with limited sun exposure or dietary intake.

Deficiency and Toxicity

• Deficiency: Vitamin D deficiency can lead to weakened bones, increased risk of fractures, muscle weakness, and a higher susceptibility to infections. Symptoms may include fatigue, bone pain, and mood changes.
• Toxicity: Excessive intake of vitamin D can lead to toxicity (hypervitaminosis D), resulting in elevated blood calcium levels (hypercalcemia), which can cause nausea, vomiting, weakness, and serious complications like kidney damage.

Conclusion

Vitamin D is a vital nutrient essential for maintaining bone health, supporting immune function, and preventing chronic diseases. Ensuring adequate intake through sunlight exposure, diet, or supplements is important for overall health.

References

1. Holick MF. “Vitamin D deficiency.” New England Journal of Medicine. 2007; 357(3): 266-281. Available from: https://doi.org/10.1056/NEJMra070553
2. National Institutes of Health. “Vitamin D – Fact Sheet for Health Professionals.” Available from: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
3. Ross AC, et al. “Dietary Reference Intakes for Calcium and Vitamin D.” Institute of Medicine. 2011. Available from: https://doi.org/10.17226/13050