The present study was an attempt to assess the cause of persistent pain in lower limbs among children from Kashmir. The study was conducted on one hundred children attending Paediatric out-patient department of Sher-i-Kashmir Institute of Medical Sciences, Srinagar. All the children were in the age group of 5 to 14 years. They showed markedly raised levels of serum alkaline phosphatase, whereas serum phosphorus, serum calcium levels and antistreptolycin O-titres were normal in 93% cases. None of them had any rheumatic or rheumatoid pathology. Among 15 suspected clinical rickets only three were established radiologically. Dietary and socio-economic history revealed deficient vitamin D intake and less exposure to sun. It was hypothesized that sub-clinical vitamin D deficiency could be a major cause of persistent pain in lower limbs and raised serum alkaline phosphatase could be the earliest marker of vitamin D deficiency. It was confirmed by injecting single dose of vitamin D (3 lac I. U.) which relieved bone pain and lowered the levels of serum alkaline phosphatase to normal within 14 weeks of initiation of therapy.