Vitamin D Deficiency

Overview

Vitamin D deficiency is common in adults with limited sun exposure, darker skin, obesity, malabsorption, or chronic kidney disease. Symptoms are vague — fatigue, muscle aches, bone pain, low mood — and diagnosis is a 25-hydroxyvitamin D level (<20 ng/mL deficient; 20–30 insufficient). Clindle orders the lab, treats with cholecalciferol (vitamin D3) — typically 2,000–5,000 IU daily for maintenance or 50,000 IU weekly for 8–12 weeks for severe deficiency — and rechecks at 3 months.