Nutrients & Supplements
D3
Vitamin D
A fat-soluble vitamin crucial for calcium absorption, immunity, and overall health.
Vitamin D is a fat-soluble secosteroid hormone synthesized in the skin upon UVB exposure and obtained from limited dietary sources. Vitamin D3 (cholecalciferol) is the preferred supplemental form. It regulates calcium and phosphorus homeostasis, supports immune function, and influences gene expression in hair follicle cycling. Deficiency is widespread globally and associated with increased risk of numerous conditions. Serum 25(OH)D levels below 30 ng/mL are considered insufficient, with optimal levels debated between 40-60 ng/mL.