This may sound far-fetched to a nutritionist, but to chemists and food scientists, this is not news. This article provides some insight as to how much you can expect to lose of some selected vitamins and minerals when processing and eating food. Food that you think may be fresh and full of the nutrients that are shown on the food label, not knowing what has been done to the food after labeling when it contained the amount of nutrients you thought you would get. Nutrition content on labels are based upon ideal conditions for the food at the time of picking and can not predict how long or under what conditions the grower stored the product, or how you will do the same, or how you will prepare it for eating.

Between the farm and the supper table the vitamin content of foods slowly disappear. The following information provided by the Vitamin and Information Service (Hoffman LaRoche) shows some typical cases of what you can expect to lose from food label content before you eat it:

Vitamin         % Loss             Cause of Loss         % Loss             Cause of Loss                    

Vitamin A           0 to 60         oxygen, heat, light
Vitamin B1         30 to 80       water, alkaline pH, heat
Vitamin B2         9 to 39         water, alkaline pH
Niacin                 3 to 27         water
Vitamin B6         30 to 82        water
Biotin                  0 to 50        oxygen, alkaline pH
Pantothenate      7 to 56        heat, water, alkaline pH, acid pH
Vitamin C           0 to 100      oxygen, heat, alkaline pH, water
Vitamin D           0 to 40        oxygen, light
Vitamin E           0 to 60        oxygen

These figures are presented to show the potential amount of loss of some vitamins during cooking (processing) and does not show losses that can arise due to storage, transportation, and temperature changes. For example, lettuce loses 50% of its vitamin C content for each day it is stored at room temperature after picking.

What about minerals? Cooking or storage usually does not destroy minerals, however, the cooking (or canning) process can leach out the minerals. The worst case, however, is the even greater variations in the mineral content of foods. Food that is grown is dependent upon the soil and added fertilizer for its nutrients. Fertilizer that is commercially used contains only the basic nitrogen, phosphorus and potassium and none of the trace minerals. No farmer can replenish the soil to its optimum conditions for the food plants to contain all of the rich minerals that it should. If it is not in the soil, it will not get in the plant, and it will not get inside you when you eat it.

A tragic example is the case of selenium, where it has a very wide variation as to its content in the soil, and many parts of the U.S. soil has no selenium in it. Yet, recent studies have shown the great importance of having selenium in the diet to help prevent heart disease and cancer. It is really sad to think that animal nutrition is far above human nutrition when cattlemen have supplemented for years their cattle's feed with selenium when grazing in selenium-poor soil.

Be it vitamin and mineral loss through processing (and storage for vitamins) or mineral deficiency through growth in or on depleted soil, it is clear that we are not getting all the nutrition that is presented to us on food labels. Notwithstanding, has anyone read the food labels lately? You barely get your RDA of vitamin C in orange juice, or calcium in milk. You best plan on consuming vast quantities of food to get what you need to prevent vitamin deficiencies. This is even more exaggerated when you think of the amounts needed to prevent disease. And what about fighting existing diseases? Forget it!