Main Causes for the Loss of Vitamin and Mineral Content in Foods

Exposure to Light:

Vitamins A, B2, D, C, E, K and Beta Carotene


Exposure to Prolonged Heat:

Vitamins A, B1, B2, B12, C and Pantothenic Acid


Exposure to Air:

Vitamins A, B12, C, D, E, K, Biotin and Folic Acid


Leaching into Cooking Water:

Vitamins B1, B2, B6, C, Magnesium, Niacin, Pantothenic Acid, Phosphorus, Potassium


Changes in pH:

Vitamins B1, B2, B12, C and Biotin (alkaline)
Folic Acid and Pantothenic Acid (alkaline or acid)



p 328-329


All this has been directly quoted from "The Essential Guide to Vitamins and Minerals" written by Elizabeth Somer, M.A., R.D. and Health Media of America.