LESSON 5  VITAMNS AND MINERALS THEIR REQUIREMENTS FOR HUMAN

 

One of the major quality aspects of our food supply is its content of vitamins and minerals. From a biological point of view, we eat to survive, and the pattern of our nutrient requirements has developed during a long evolutionary process in which man has adapted to his environment. Although certain food process, such as cooking, are indeed very old, it is only within the last 150 years that we have begun to consume significant part of our food in a factory-processed form.

Our modern processed food supply has contributed enormously to the public health status of the population. Certain nutritional diseases, which were common in parts of the United States 50 years ago, such as pellagra, have all but disappeared. A recent ten-states nutritional survey demonstrated that while nutritional deficiencies did exist, they were minimal compared to what existed prior to the modern era of nutrition and food technology.Consider that it is now possible to eat a diet balanced in all types of foods at any time of year and in any geographical location.

At the same time, modern process technology has also introduced its share of problems. Sometimes this has been a result of inadequate knowledge, but tragic cases of illness and even death have occurred where essential nutrient value has been lost because of ignorance, carelessness, and lack of adherence to “good manufacturing practice.” In the past, new food processes have seldom been assessed for their contribution to nutrient loss or retention.

Multiple processes, such as freezing of reconstituted dehydrated foods, may lead to benefits in process scheduling, but they may also lead to higher than normal losses of vitamins. New forms of food products, such as intermediate moisture food, may lead to accentuated problems of vitamin stability. A food product, to have acceptable nutritional quality, Should generally be capable of providing those nutrients normally characteristic of its food group.

It is the purpose of this lesson to summarize the available information on the requirements of vitamins and minerals for human.

 

Vitamin and Mineral Requirements and Allowances

 

 In order to understand whether a specific treatment of a specific food leads to acceptable nutrient quality, it is necessary to have an understanding of both human requirements and the amount of a specific nutrient present in the food after normal preparatory procedures.

The concentrations of many of the key nutrients are given for fresh and cooked foods in USDA Handbook No.8. Although data in this compilation are occasionally inaccurate, they afford the only major source of information apart from direct analysis of the product in question.In many instances, inaccuracies are caused by analytic procedures of insufficient specificity, and users of these data should be especially cognizant of the appropriateness of the methodology

    The presently accepted status of human dietary requirements is well summarized in the Recommended Dietary Allowances (RDA) of the Food and Nutrition Board, National Academy of Sciences-National Research Council.

Since both males and females of different age classes have been assigned different RDA’s, it is simpler to consider a mean value for each nutrient. Mean values for men and women ages 23—50 years are summarized in Table 5-1. It is appropriate deal with nutrients that have neither established nor approximated RNA’s in a quantitative fusion. However, one should remain aware of the fact they are essential.

 

Enrichment, Restoration, and Fortification

 

The addition of nutrients to foods may be undertaken for a variety of purposes. Definitions of the various terms associated with addition of nutrients are:

1.     Restoration: Addition to restore the original nutrient content.

2.     Fortification: Addition of nutrients in amounts significant enough to render the food a good to superior source of the added nutrients. This may include addition of nutrients not normally associated with the food or addition to levels above that in the unprocessed food.

3.     Enrichment: Addition of specific amounts of selected nutrients in accordance with a standard of identity as defined by the United States Food and Drug Administration.

The Joint Policy Statement by the Council on Foods and Nutrition of the American Medical Association and the Food and Nutrition Board of the National Academy of Sciences-National Research Council, published in August 1968, endorses continuation of nutrient addition programs. The specific endorsement states.

The enrichment of flour, bread, degerminated corn meal, corn grits, whole grain corn meal. And white rice (with thiamine, riboflavin, niacin, and iron); the retention or restoration of thiamine, riboflavin, niacin, and iron in processed food cereals; the addition of vitamin D to margarine; fluid skimmed milk, and nonfat dry milk; and the addition of vitamin A to margarine; fluid skimmed milk, and nonfat dry milk; and the addition of iodine to table salt; the protective action of fluoride against dental caries is recognized, and the standardized addition of fluoride is endorsed in areas in which the water supply has a low fluoride content.

In addition, the Council on Foods and Nutrition and the Food and Nutrition Board in the same policy statement continue to endorse the addition of nutrients to foods under all of the following circumstance:

1. When the intake of the nutrients is below the desirable level in the diets of a significant number of people.

2. When the food used to supply the nutrient is likely to be consumed in quantities that make a significant contribution to the diet of the population in need.          

3. When the addition of the nutrient is not likely to create an imbalance of essential nutrients.

4. When the nutrient added is stable under proper conditions of storage and use.

5. When the nutrient is physiologically available to the consumer.

6. When there is reasonable assurance against excessive intake to a level of toxicity.