Vitamin D and Its Metabolites in Human and Bovine Milk

Abstract

Human and bovine milk were analyzed for vitamin D, 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, 25,26-dihydroxyvitamin D and 1,25-dihydroxyvitamin D using exhaustive chromatographic purification procedures coupled with ligand binding assays. Human milk contained the following amounts of antirachitic sterols (pg/ml, mean +/- SD, n = 5): 39 +/- 9 vitamin D; 311 +/- 31 25-hydroxyvitamin D; 52 +/- 8 24,25-hydroxyvitamin D; 32 +/- 9 25,26-dihydroxyvitamin D; 5.1 +/- 0.3 1,25-dihydroxyvitamin D. Normal bovine milk contained levels of these sterols comparable to those found in human milk. Increasing the oral dose of vitamin D to the cows was reflected by an increase of the parent vitamin and 25-hydroxyvitamin D in the milk. Vitamin D-binding protein concentration in human milk whey, determined by Ouchterlony immunodiffusion and radioimmunoassay, was 1--2% of the levels observed in the plasma and was dependent on the stage of lactation. Vitamin D and its metabolites were shown initially to be present in the whey portion but with time migrated into the fat portion of milk. The antirachitic sterols detected account for approximately 25 IU/liter and 27 IU/liter of antirachitic activity in human and bovine milk, respectively. In both species 25-hydroxyvitamin D comprised the majority of the antirachitic sterols detected in normal milk.

Prevention of Rickets and Vitamin D Deficiency in Infants, Children, and Adolescents

“…[71][72][73][74]126 In a lactating mother supplemented with 400 IU/day of vitamin D, the vitamin D content of her milk ranges from Ͻ25 to 78 IU/L. 73,74,[126][127][128][129] Infants who are exclusively breastfed but who do not receive supplemental vitamin D or adequate sunlight exposure are at increased risk of developing vitamin D deficiency and/or rickets. 7,[10][11][12]14,18,81,130 Infants with darker pigmentation are at greater risk of vitamin D deficiency, 131 a fact explained by the greater risk of deficiency at birth 132 and the decreased vitamin D content in milk from women who themselves are deficient.…”

Nutritional rickets among children of Northern Kerala, India

“…Breast milk is indisputably the ideal food for infants; however, breast milk typically contains about 25 IU/L which is insufficient for rickets prevention. 15,16 Although there is evidence that limited sun exposure may prevent rickets in some breast-fed infants concerns over the health risk of sun exposure had led to the recommendation that all breast-fed infants receive supplemental vitamin D. 17,18 Thacher et al reported that children with rickets had a greater proportion of first degree relatives with a history of rickets. 19 A similar diet and environment may be the reason for rickets in families.…”

Vitamin D Efficiency in Pregnancy: An Updated Viewpoint in Indian Scenario

“…In most infants, Vitamin D stores acquired from the mother are depleted by approximately 8 weeks of age [43]. Human milk contains a very low concentration of Vitamin D (approximately 20 -60 IU/L), which represents 1.5% -3% of the maternal level [44]. This low concentration is not sufficient to maintain an optimal Vitamin D level in the newborns if exposure to sunlight is limited.…”