Serum 25-hydroxy-vitamin D levels in malnourished children with rickets.

Serum levels of calcium, phosphorus, alkaline phosphatase, and 25 hydroxy-vitamin D (25-OH-D3) were measured in normal and malnourished children with and without rickets. Children with rickets had clinical, biochemical, and x-ray evidence of the disease; most of them were malnourished. 25-OH-D3 levels were lower than in normal children. After treatment with vitamin D their condition improved. 25-OH-D3 levels were also found to be reduced in malnourished children without rickets. These studies show that rickets is common in malnourished children. Inadequate exposure to sunlight appears to be the factor mainly responsible for the high incidence of the disease. In addition, malnutrition perhaps contributes to the development of rickets.