The objectives of this study were to investigate the effect of different cooking methods including blanching, boiling, microwaving, and steaming, on the content and true retention of vitamins (i.e. β-carotene, ascorbic acid and vitamins E and K) in vegetables. Mushrooms hold onto most of their nutrients surprisingly well during cooking. B vitamins like riboflavin, niacin, and pantothenic acid show 100% retention when stir-fried or microwaved, according to USDA testing. USDA FoodData Central produces thorough resources for navigating and understanding nutritional info to support dietary choices and nutritional analysis. The USDA FoodData Central search function provides nutrient data for food components based on individually researched samples. The true retention was statistically significantly lower for vitamin D 2 (p 0.0001) when mushrooms were boiled (at either pH 5.5 or 3.5) compared to mushrooms that were dry-fried or baked. USDA FoodData Central nutrient data for Mushrooms, white, cooked, boiled, drained, with salt (FDC 168537), used in the RawPawIQ Nutrition Database. Nutrient retention factors are given for a range of cooking and preparation methods such as, but not limited to, baked, boiled, reheated, broiled, pared, and drained.