Saturday, November 04, 2006

Short History of Vitamin D

Hippocrates, the father of medicine, used heliotherapy or exposure to sunlight to treat phthisis.

The Greek historian, Herodotus (485-426 BC), observed that Persian warriors had much softer skulls than Egyptian warriors and attributed it to the turbans worn by Persians and Hippocrates described as disease resembling rickets in 130 AD.

The first scientific description of a vitamin D-deficiency, namely rickets, was provided in the 17th century by both Dr. Daniel Whistler (1645) and Professor Francis Glisson (1650).

Cod liver oil was first described as a medicinal agent for the treatment of chronic rheumatism in 1789.

Rickets captured the imagination of many chroniclers of the eighteenth and nineteenth centuries. The cause of this was a lack of a vitamin that is not a vitamin.

Beginning in the 1820s, studies showed that administering doses of cod liver oil to afflicted children could cure rickets.

The major breakthrough in understanding the causative factors of rickets was the development in the period 1910 - 1930 of nutrition as an experimental science and the appreciation of the existence of vitamins.

It was in 1919/20 that Sir Edward Mellanby, working with dogs raised exclusively indoors (in the absence of sunlight or ultraviolet light), devised a diet that allowed him to unequivocally establish that the bone disease, rickets was caused by a deficiency of a trace component present in the diet.

In 1921 he wrote, "The action of fats in rickets is due to a vitamin or accessory food factor which they contain, probably identical with the fat-soluble vitamin."

Shortly thereafter E. V McCollum and McCallum succeeded in inducing a rickets-like disease in chickens by administering an incomplete diet. The disease could be cured with cod-liver oil. They assumed that vitamin, present in cod-liver oil, was responsible for the curative effect.

In 1923 Goldblatt and Soames clearly identified that when a precursor of vitamin D in the skin (7-dehydrocholestrol) was irradiated with sunlight or ultraviolet light, a substance equivalent to the fat-soluble vitamin was produced.

Huldschinsky, Hess and Steenbock in 1924 found that a great number of foodstuff, having no antirachitic properties, became antirachitic after irradiation with sunlight or ultraviolet light. The substance activated by sunlight was called ‘provitamin D.’

Several other independent observations in the 19th and early 20th centuries fostered further links between sunlight and cutaneous vitamin D synthesis.

The first analogue of the vitamins D were determined in the 1930s in the laboratory of Professor A. Windaus at the University of Gottingen in Germany.

With the chemical isolation and finally synthesis of the two parent or native D vitamins, vitamin D2 (egocalciferol) and vitamin D3 (cholecalciferol), an etiology therapy for rickets and osteomalacia was established.

Vitamin D2 which could be produced by ultraviolet irradiation of ergosterol was chemically characterized in 1932. Vitamin D3 was not chemically characterized until 1936 when it was shown to result from the ultraviolet irradiation of 7-dehydrocholesterol.

In 1970, it is learned that vitamin D was not the biological active principle for healing bone disease.
Short History of Vitamin D

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