Stability of vitamin D3 and vitamin D2 in oil, fish and mushrooms after household cooking

Information on the retention of vitamin D in food following household cooking is scarce. So far the retention of its metabolites vitamin D3, vitamin D-2, and 25-hydroxyvitamin D-3 has shown that the type of food and the cooking method are the essential determinants, and there is no significant difference between the metabolites. We investigated the retention of vitamin D-3 and vitamin D-2 in sunflower oil, vitamin D-3 in rainbow trout, and vitamin D-2 in button mushrooms. The investigated cooking methods were boiling at different pH, steam cooking, microwave cooking, pan-frying, and oven baking. There was no difference between the retention of vitamin D-3 and vitamin D-2 added to sunflower oil, which ranged from 70 to 99%. In rainbow trout, the retention of vitamin D-3 at 85-114% was not significantly different from 100%, except for panfrying at 85%. However, the retention of vitamin D-2 in mushrooms at 62-88% was significantly different from 100% (p <= 0.05).