Effect of Household Cooking on the Vitamin D content in Fish, Eggs, and Wild Mushrooms

The retentions of cholecalciferol in fish and egg yolk, 25-hydroxycholecalciferol in egg yolk, and ergocalciferol in wild mushrooms after normal household cooking were studied. The fish samples were baked at 172 or 200°C for 20 min, the egg yolk samples were cooked in boiling water for 10 min, and mushroom samples were fried in a hot pan for 5 min. In addition, the storage stabilities of cholecalciferol and 25-hydroxycholecalciferol in egg yolk and ergocalciferol in mushrooms were tested. The vitamin D compounds were determined from the raw material reference (control sample), and from processed and stored samples using a high-performance liquid chromatographic (HPLC) method with an internal standard. Fat content in the fish samples and dry matter content in all samples were also analyzed. In general, the losses of vitamin D compounds were <10%, hence, household cooking would seem not to lessen intake of vitamin D from foods.