Vitamin D in human milk

Abstract

Vitamin D is one of the fat‐soluble vitamins. Its function in the body is to promote the absorption of calcium from the intestine and deposition of calcium in developing bone. If the young child does not have sufficient vitamin D he develops rickets. Vitamin D can be obtained in two ways, from the food, or by the action of the ultraviolet rays of the sunlight on a fatty substance, 7 dehydrocholesterol, in the deeper layers of the skin. There is at present no method for making a quantitative assessment of the amount of vitamin D obtained in this way, but it is believed to be the natural and most important means by which the body acquires its vitamin D. However, if a person does not expose his body to the sunlight, either because he (or more likely she) covers it up when she goes out, or stays indoors, or lives in northern parts of the world where there is no sunlight for many months of the year, there can be no conversion of 7 dehydrocholesterol to vitamin D. Even as far south as Scotland in the winter there is virtually no ultraviolet light. Vitamin D can be stored in the liver and body fat, so that a sunny summer may allow a store to be built up which can be drawn upon in the winter. However, whenever sunlight and particularly ultraviolet light does not reach exposed parts of the skin dietary sources of vitamin D become of major importance. The richest dietary sources of vitamin D are fatty fish such as herrings, kippers, pilchards and mackerel, but few people eat enough of these fish for them to be an important day to day provider of the vitamin. Most of our dietary vitamin D comes from margarine which is fortified with the vitamin, and eggs. Egg yolk contains about 5 micrograms of vitamin D per 100 grams, fortified margarine 8 micrograms and herrings, bloaters and kippers 25 micrograms per 100 grams.

Citation

Widdowson, E.M. (1979), "Vitamin D in human milk", Nutrition & Food Science, Vol. 79 No. 3, pp. 4-5. https://doi.org/10.1108/eb058751