Metabolic studies in congenital vitamin D deficiency rickets

Abstract

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.

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

“…Moreover, in areas where severe vitamin D deficiency rickets is endemic, it has been effectively treated with breast milk as the only form of nutrition in mothers who received 150,000 IU vitamin D every 3 mo, or ϳ1,800 IU/day (902,903). These babies and their mothers were protected from sun exposure and had negligible vitamin D in the diet, so a maternal supplement was the main source.…”

“…This includes cohort studies that have examined low maternal vitamin D intakes and 25OHD concentrations (731), and randomized interventions which found that maternal intake of 2,000 -6,400 IU vitamin D/day failed to change the calcium content of milk compared with an intake of 400 IU/day (60,402,965), even though the 6,400 IU dose raised maternal 25OHD to 160 nM (64 ng/ml) (965). On the other hand, several individual cases from India revealed that milk calcium content was lower in mothers presenting with overt vitamin D deficiency with mean 25OHD values of 6 nM (2.5 ng/ml), hypocalcemia, hypophosphatemia, and markedly elevated PTH (903). These results confirm that calcitriol likely does not play a direct role in causing calcium to enter milk, but extremes of vitamin D deficiency (25OHD closer to 6 nM) will impair milk production.…”

Bone Development and Mineral Homeostasis in the Fetus and Neonate: Roles of the Calciotropic and Phosphotropic Hormones

“…Over 16 years Teotia et al (666) examined 165 babies born of women with severe osteomalacia. Of these, only six babies showed abnormalities: three had postnatal hypocalcemia and three had postnatal rickets without hypocalcemia (666). In another paper summarizing their experience, Teotia et al (667) wrote that congenital rickets is "uncommon and develops only when maternal mineral and vitamin D stores have been completely exhausted.…”

“…In other reports that described rickets as being present "at birth," the diagnosis was actually made within the first or second week after birth, so the skeletal status at birth remains unknown (50,59,191,451,502,585,586,666). "Neonatal rickets" is a more appropriate term for such cases, as opposed to "congenital rickets," because the latter implies that the condition was present at birth.…”

“…Instead, the mothers had such problems as severe anorexia, malnutrition, malabsorption from celiac disease or pancreatic insufficiency, lactose intolerance, extreme avoidance of calcium and dairy food sources, use of drugs that interfere with vitamin D metabolism, or very low intakes of both calcium and vitamin D (50,279,426,428,448,543,632,666). This fits with Teotia's impression that rickets will be present at birth only in extreme cases of complete nutritional exhaustion (667), or as Maxwell described in 1935, "women who have, in the matter of diet, been living near the starvation-line."…”