Feto-maternal relationships between vitamin D metabolites in Israeli Bedouins and Jews

The major metabolites of vitamin D, 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1,25-dihydroxyvitamin D were assayed in the blood of mothers at delivery and in the cord blood of their infants. Twelve Bedouin women and nine Jewish women were investigated; all lived in the Negev desert in Israel. All three vitamin D metabolites were significantly lower in cord than in maternal blood in both groups. Bedouin mothers and infants had significantly lower levels of 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D than did Jewish mothers and infants. Concentrations of 1,25-dihydroxyvitamin D did not differ significantly between the ethnic groups and in both maternal groups were well above the normal range (Bedouins 83.6 pg/ml ± 11.3; Jews 98.6 pg/ml ± 12.3). Cord and maternal values for this metabolite were significantly correlated (r = 0.71, p < 0.001).