Limited vitamin D intake and use of sunscreens may lead to rickets

EDITOR—I would like to add a sixth suggestion to Wharton's five approaches to improving children's vitamin D status to prevent rickets.1 A case of rickets was recently diagnosed in a 12 month old white infant at the Hospital for Sick Children in Toronto. He had clinical, radiological, and biochemical evidence of rickets, which responded to vitamin D treatment. Vitamin D intake seemed adequate until six months after treatment began but was sporadic after that. Although the infant spent time outdoors in the summer, his skin was protected with potent sunscreens (SPF 30).

Rickets presumably developed because of limited vitamin D intake combined with diminished skin penetration of ultraviolet radiation. I believe that …