Thirty paired samples of the same brand of UHT (ultra-high temperature treated) whole milk (3.5% butterfat) and UHT skimmed milk (0.5% butterfat) of Zimbabwean origin were randomly acquired from commercial sources. Measurements of this nature help in providing a quantitative basis for universal fortification and prevention of vitamin A deficiency diseases in developing nations. The objective of the present study was to quantify the reduction in vitamin A content when bovine standardised whole milk (3.5% butterfat) is converted to skimmed milk (0.5% butterfat). A dearth of scientific studies and data overshadows the effects of skimming on the status of fat-soluble vitamins. 5 Although the above values are expected to be significantly reduced in skimmed milk, public literature is inundated with the health benefits of fat-free milk, as portrayed in advertisements in various newspapers and magazines.
Important seasonal variations have, however, been documented such that the vitamin A content of whole milk ranges between 200 and 480 μg/L. According to previous reports, whole milk contains on average 310 μg/L 4 of vitamin A (1 IU = 0.3 μg/L). 2 Despite the lesser nutritional contribution, vitamin E in milk helps to slow down peroxidation of lipids 3 and thus enhances the bioavailability of vitamin A as well as other fat-soluble vitamins. A daily serving of 244 ml of cow’s whole milk contributes 7.6% to the recommended dietary allowance for vitamin A and only 1% to the RDA for vitamin E. Vitamin A and vitamin E, on the other hand, have to be obtained from external sources. Likewise vitamin K can be obtained from synthetic activities of symbiotic bacteria resident in the colon. However, the healthy organism is able to synthesise vitamin D beginning with the action of ultraviolet light on cholesterol in the skin. 1 Extraction of butterfat from milk during skimming is therefore expected to result in substantial loss of fat-soluble vitamins. In addition, butterfat contains β-carotene, which upon ingestion serves as a precursor for synthesis of vitamin A. The fat-soluble vitamins A (retinol), D (1,25 dihydroxycholecalciferol), E (α-tocopherol) and K (2-methyl-3-phytal-1, 4-naphthoquinone) are normally associated with the butterfat content of milk. The results emphasise the need for fortification of skimmed milk with vitamin A in order to augment the prevention of vitamin A deficiency diseases in developing countries.Īmongst all natural foods and beverages milk is unique in that it contains all known water-soluble and fat-soluble vitamins. The 85.7% reduction in butterfat content from 3.5% in whole milk to 0.5% in skimmed milk was accompanied by an 82.824 ± 3.51% (mean ± SD) reduction in retinol content.Ĭonclusion: The contribution of milk to the RDA for vitamin A was reduced from the standard 7.6% for whole milk to 1.30% for skimmed milk with 0.5% fat.
Results: Absolute concentration of vitamin A was reduced from 208.830 ± 0.083 μg/L in whole milk to 35.855 ± 0.046 μg/L in skimmed milk. Outcome measures: Thirty paired samples ( n = 30) of whole milk and skimmed milk were evaluated for vitamin A content using UV-visible light spectrophotometry at 328 nm. Sampling and analysis were performed by different individuals to achieve a randomised blind design. Objective: To compare the levels of vitamin A in ultra-high temperature treated (UHT) whole milk (3.5% fat) and UHT skimmed milk (0.5% fat) using UV-visible light spectrophotometry and to compare the contribution of whole milk and skimmed milk to the recommended dietary allowance (RDA) for vitamin A.ĭesign: Paired samples of liquid whole milk and liquid skimmed milk were used.
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