Nutritional rickets in young Nigerian children in the Sahel savanna.

Objectives: To determine the prevalence of clinical and biochemical rickets in an under-five out-patient population, relate the prevalence of biochemical rickets (BR) to the sociocultural characteristics of families and determine the response of nutritional rickets to vitamin D therapy.

Design: Prospective cross-sectional and retrospective case-series surveys.

Setting: Paediatric general out-patient and consultant clinics.

Subjects: One hundred and ninety eight out-patients and twenty two patients aged >1 to 60 months treated for nutritional rickets.

Interventions: Clinical examination, interview with mothers and determination of biochemical abnormalities of under-fives and management of patients with rickets using stosstherapy.

Main Outcome Measures: Prevalence of BR and response to stosstherapy.

Results: Eight (4%) patients in the survey had clinical and biochemical rickets while 33 (17%) had biochemical rickets only; 92 (47%) other patients had isolated hypocalcaemia and/or hypophosphataemia. The prevalence of BR was higher in males (p <0.05), and increased with age (p <0.001). The prevalence was lower in families who were indigenous to the area (p <0.05), children of Moslem families (p <0.05) and children whose mothers were full-time housewives, unskilled or traders (p <0.01), and who lacked any formal western education (p = 0.157). Three of the seven evaluable patients who received stosstherapy responded late.

Conclusion: The results support the hypothesis that deficiency or reduced availability of dietary calcium may be of at least equal importance with vitamin D deficiency in the aetiology of nutritional rickets in the Sahel savanna.