Search

Nutritional rickets is caused by vitamin D deficiency due to lack of exposure to sunlight. Neonatal rickets occurs only in infants born to mothers with very severe osteomalacia. Calcium deficiency alone does not cause mineralisation defects. It only causes osteoporosis and secondary hyperparathyroidism with raised plasma, 1,25 (OH)2D and osteocalcin. Low 25-OHD, increased IPTH, increased alkaline phosphatase in plasma and decreased calcium and increased hydroxyproline in urine are diagnostic of rickets. Low or undetectable plasma levels of 25-OHD, in presence of high plasma 1,25(OH)2D and IPTH are often observed during treatment with vitamin D. Even the marginal intakes of fluoride (> 2.5 mg/day) cause rickets in calcium deficient children. Indian children often need high dose of vitamin D due to severely depleted D stores, high IPTH and severe bone disease (radiologic and histomorphometric) for treatment.

Congenital rickets in 3 newborns of mothers with advanced nutritional osteomalacia, healed with maternal breast milk feeding when mothers alone were given calcium supplements and 7.5 mg of intravenous D2 and the mother baby pair protected from sunlight. Maternal plasma biochemistry indicated more severe vitamin D deficiency compared to their newborns (intrauterine foetal priority). The first dose of 7.5 mg of vitamin D3 and calcium supplements to mother healed osteomalacia but did not appear to heal the rickets of their breast fed infants (extrauterine maternal priority for vitamin D). A second dose given at 3 months interval healed the rickets in their infants and the biochemistry of the mother and baby returned towards normal. Congenital rickets developed when maternal bone mineral and vitamin D stores had been completely exhausted. Raised IPTH levels in the newborn suggested that foetal parathyroids were responsive to hypocalcaemic stimulus.