Vitamin D levels in children with growing pains

To estimate the serum levels of vitamin D in children with growing pains and determine the relationship between serum vitamin D levels, parathormone and routine biochemical markers.

Cross-sectional study.

Department of Paediatrics, Liaquat National Hospital, Karachi, from October 2008 to September 2009.

Hundred children, aged 5-12 years presenting in Paediatric Outpatient Department of Liaquat National Hospital, Karachi, with limb pains, fulfilling the diagnostic criteria of growing pains, were included. Children with any systemic illness, organic cause of pain, rheumatologic disorders and signs of rickets were excluded from the study. Children were investigated for serum total calcium, inorganic phosphorus, alkaline phosphatase, vitamin D3 (25-hydroxecholecalciferol) and parathormone levels. On the basis of serum vitamin D3 level, patients were divided into 3 groups; group 1 with normal level of vitamin D3 (> 75 nmol/L), group 2 with vitamin D insufficiency (level between 50-75 nmol/L), and group 3 with vitamin D deficiency (level < 50 nmol/L). Significance of group proportions was determined using chi-square test with significance at p < 0.05.

The mean age of the participants was 8.05 years with the majority (59%) being females. Only 6% had normal vitamin D levels. Over 95% of the children with vitamin D insufficiency had normal alkaline phosphatase and parathormone levels.

Hypovitaminosis D may have a role in pathogenesis of growing pains. All children with unexplained limb pains without identifiable organic pathology should be tested for vitamin D status, and treated, if necessary. Routine biochemical markers alone are not sufficient to detect all cases of hypovitaminosis D.