Background: Nutritional rickets is a disease of growing children leading to bone deformities, bone pain, convulsions or delayed motor development. Today, high-incidence of nutritional rickets is mainly found in low-income countries.
Objectives: To assess the effects of various interventions on the prevention of nutritional rickets in term born children.
Search strategy: Studies were obtained from computerised searches of The Cochrane Library, MEDLINE, EMBASE, LILACS and reference lists of relevant articles. We contacted authors of studies or reviews to obtain further studies.
Selection criteria: Studies were included if they were randomised controlled clinical trials, controlled clinical trials or prospective cohort studies comparing any intervention for the prevention of nutritional rickets in term born children with placebo or no intervention. Minimum duration of the intervention was three months for children under 12 months or six months for children over 12 months.
Data collection and analysis: Two authors independently extracted data and assessed study quality. Authors of studies were contacted to obtain missing information.
Main results: Four studies enrolled approximately 1700 participants. Trials lasted between nine months to two years. Three studies were randomised controlled trials, two of which showed a cluster randomised design; one trial probably was a controlled trial with researcher controlled group assignment. In children up to three years of age in Turkey, Vitamin D compared to no intervention showed a relative risk of 0.04 (95% confidence interval (CI) 0 to 0.71). Despite a marked non-compliance, a Chinese trial in children up to three years of age comparing a combined intervention of supplementation of vitamin D, calcium and nutritional counseling showed a relative risk of 0.76 (95% CI 0.61 to 0.95) compared to no intervention. In two studies conducted in older children in China and in France no rickets occurred in both the intervention and control group.
Authors' conclusions: There a only few studies on the prevention of nutritional rickets in term born children. Until new data become available, it appears sound to offer preventive measures (vitamin D or calcium) to groups of high risk, like infants and toddlers; children living in Africa, Asia or the Middle East or migrated children from these regions into areas where rickets is not frequent. Due to a marked clinical heterogeneity and the scarcity of data, the main and adverse effects of preventive measures against nutritional rickets should be investigated in different countries, different age groups and in children of different ethnic origin.