Vitamin D4 in mushrooms and yeast
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Vitamin D deficiency is a pandemic that is now one of the most common nutritional deficiencies worldwide. Vitamin D deficiency leads to reduced calcium absorption from our diet, which causes hyperparathyroidism. The increase in parathyroid hormone results in a defective mineralization of our skeleton, leading to the development of rickets in children and osteomalacia in adults. It also increases bone reabsorption resulting in a decrease in bone mineral density. During the winter months there is decreased or complete absence of the production of vitamin D in the skin; therefore finding natural dietary sources of vitamin D becomes important. Some mushroom species exposed to ultraviolet radiation produce vitamin D2 as well as vitamin D4. The goal of this project was to use high performance liquid chromatography with a photodiode ultraviolet absorbance detector to identify which provitamin Ds and vitamin Ds were present in various edible mushrooms species including skiitake (Lentinus edodes), oyster (Pleurotus ostreatus), portabella (Agaricus bisporus), crimini (Agaricus bisporus), and white button (Agaricus bisporus); and the yeast species Saccharomyces cerevisiae (Baker's yeast). Provitamin Ds and vitamin Ds from the mushroom powder (Monterey Mushroom), mushroom samples, and the yeast sample were extracted with methanol and run on a Zorbax CN column. All the provitamin D samples were analyzed with reverse phase HPLC on a Zorbax ODS column along with standards for provitamin D2 (ergosterol), provitamin D3 (7-dehydrocholesterol), and provitamin D4 (22,23-dihydroergosterol). The collected vitamin D samples were run on a Vydac C18 column along with standards for vitamin D2 (ergocalciferol), vitamin D3 (cholecalciferol) and vitamin D4. Provitamin D4 and vitamin D4 isolated and collected from the mushroom powder sample were used as standards. Provitamin D4 was identified in every mushroom species as well as the yeast sample. Vitamin D4 was identified in three of the UV irradiated mushroom species including; white button, shiitake and oyster, as well as the yeast sample. Provitamin D3 was identified in a shiitake mushroom. The ultraviolet absorption spectra for compounds identified as vitamin D2, vitamin D4, provitamin D2, provitamin D3 and provitamin D4 in all samples matched the UV absorption spectra of a 5,6-cis-triene of vitamin D and a 5,7-diene of provitamin D standards. These results demonstrate that in addition to vitamin D2, some mushroom species and the yeast Saccharomyces cerevisiae can also produce vitamin D4. In addition, shiitake mushrooms contain provitamin D3, and thus has the ability to produce vitamin D3 after exposure to UV radiation. Mushrooms and yeast are therefore a natural dietary source of multiple vitamin Ds.
Thesis (M.A.)--Boston University