Also known as: cholecalciferol, ergocalciferol, vitamin d3, vitamin d2, d3
Fat-soluble vitamin produced in skin upon sun exposure. Critical for calcium absorption, bone health, immune function, and mood regulation. Widespread deficiency globally.
Essential for calcium absorption. Deficiency leads to rickets in children and osteomalacia in adults — a well-established causal relationship.
May reduce risk of respiratory infections. Active area of research.
Some association between low vitamin D levels and depression, but evidence is inconsistent.
Always consult your healthcare provider before combining supplements with medications.