AIM The aim of this study was to evaluate the uptake of a free vitamin D infant prescription programme and to determine the incidence of nutritional rickets. METHODS This was a retrospective cohort study of infants from Quebec, Canada, involving term infants born between 1998 and 2008 and covered by the public insurance programme. Data were extracted from the Quebec Pregnancy Cohort. Predictors of programme participation were identified through logistic regression. RESULTS A total of 123 018 infants were eligible, and the mean annual prevalence of supplemental vitamin D exposure was 17.9 ± 5.6%. The median age for obtaining the first bottle was 36 days and half only obtained one bottle of 50 doses. Mothers with higher socio-economic status, those who lived as a couple, older mothers or a prescription by a paediatrician significantly increased the odds of obtaining vitamin D. There was a decline in programme participation over time (OR 0.89/year, 95% CI = 0.88-0.90). The incidence of rickets was 23.9 cases per 100 000 live births, with an annual increase of 1.12 cases/year (95% CI = 1.01-1.24). CONCLUSION Without educational measures, a free prescription programme for vitamin D failed to encourage participation or adherence. Moreover, participation decreased with time. New strategies, including educational support, need to be developed to increase vitamin D supplementation rates.