What Is Vitamin D Deficiency?

Vitamin D deficiency is defined as a 25-OH vitamin D level below 20 ng/mL.

Thresholds

• Severe: below 12 ng/mL
• Deficient: 12–20 ng/mL
• Insufficient: 20–30 ng/mL
• Sufficient: 30–50 ng/mL

Symptoms

• Bone pain
• Muscle weakness
• Fatigue
• Frequent infections
• Depression

Causes

• Limited sun exposure
• Dark skin
• Obesity
• Malabsorption
• Kidney/liver disease
• Age

Treatment

• 50,000 IU weekly for 8 weeks
• Then 1,500–2,000 IU/day maintenance
• Recheck in 8–12 weeks