Influence of Dietary Cholesterol on Vitamin D Metabolism in Formula‐Fed Preterm Neonates

Abstract

ObjectivesSupplementation of preterm formulas with cholesterol could help to mimic the fat composition of human milk. However, this could possibly influence vitamin D 25‐hydroxylation because this reaction is catalyzed in part by the mitochondrial cytochrome P‐450, the enzyme responsible for the 27‐hydroxylation of cholesterol. The purpose of this study was to verify whether the addition of cholesterol to preterm formulas could interfere with vitamin D metabolism in preterm neonates.MethodsIn a prospective study, 30 preterm neonates were randomly assigned to a low (< 0.03 g/L), medium (0.15 g/L), or high (0.30 g/L) cholesterol‐content preterm formula until theoretical term (i.e., 40 weeks post‐conceptional age). Anthropometric data and serum hydroxy‐vitamin D and 1,25 dihydroxy‐vitamin D concentrations were measured at study entry and theoretical term. In a subgroup of 14 subjects, serum cholesterol and lymphocyte 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase mRNA were also assessed.Results(median [25th, 75 th centiles]): At theoretical term, there were no significant differences in serum hydroxy‐vitamin D concentrations among the three groups, even after adjustment for confounding variables (65 [50, 78] nmol/L, 79 [59, 86] nmol/L, and 67 [43, 103] nmol/L, respectively, P = 0.65) or 1,25 dihydroxy‐vitamin D (P = 0.88). Furthermore, there were no significant differences in 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase mRNA copy numbers.ConclusionsIn preterm neonates fed formulas with a cholesterol content similar to or higher than that of human milk, we did not observe deleterious effects on vitamin D metabolism. However, long‐term effects of cholesterol supplementation require further studies.