Vitamin D metabolites in bovine milk and butter

The main goal of this study was to establish the content of vitamin D-3, 25-hydroxyvitamin D-3 (25OHD(3)), vitamin D-2, and 25-hydroxyvitamin D-2 (25OHD(2)) in dairy products. Composite samples of milk cream,, and butter (1.5-80% fat), and organic milk (3.5% fat) were analyzed. Each composite sample was sampled over 3 months and the sample comprised 12 units (range 8-14). The average content of vitamin D3 and 25OHD(3) were 4.6-196 ng/100 g and 4.2-96 ng/100 g, respectively. For vitamin D2 the values in milk and, butter, were 3.4 and 61 ng/100 g, respectively, and for 25OHD(2) they were 3.1 and 58 ng/100 g, respectively. Statistically significant effects of food product (p < 0.0001) and season (p < 0.05) on the content of vitamin D-3 and 25OHD(3) were shown. Vitamin D-3 and 25OHD(3) were significantly associated with fat (R = 0.88, p < 0.0001 and R = 0.96, p < 0.0001, respectively). Differences were observed between organically and conventionally produced milk. Implementation of these values into Food Databanks has to be done carefully, due in part to a lack of consensus on the relative bioactivity between the vitamin D active compounds, and partly because quantification of dihydroxy vitamin D compounds were not included in this study. (C) 2009 Elsevier Inc. All rights reserved.