OBJECTIVE: To determine vitamin D levels among children 6 to 23 months old receiving services from Women, Infants, and Children (WIC) programs in Alaska.Study design During 2001 and 2002, we recruited 133 children receiving services at seven WIC clinics, administered a risk factor questionnaire, and collected blood. RESULTS: Fifteen (11%) and 26 (20%) children, respectively, had vitamin D levels or =25 ng/mL. Among 41 still breast-feeding children, 14 (34%) took supplemental vitamins, and six (18%) were reported to have received vitamins every day. CONCLUSIONS: Vitamin D deficiency is prevalent in Alaska. Breast-feeding in the absence of adequate vitamin D supplementation is the greatest risk factor.