Definition & Etiology
Definition
- Fat-soluble vitamin
- Regulates calcium and phosphate homeostasis, vital for MSK health
- 2 types: D2 and D3 (cholecalciferol – most common)
- Converted into these active forms via the kidney and liver (via PTH)
- >50nmol/l = normal
- 25-50nmol/l = insufficiency
- <25 nmol/l = deficiency
Prevalence
- Common in adults and children
Etiology
- Insufficient sunlight exposure
- Dietary
- Malabsorption
- Impaired conversion (liver/kidney disease)