Keeping Vitamin Values Intact

smart review online — Thu, 22 Oct 2009 13:48:25 +0000

Keeping Vitamin Values Intact

Many vitamins are readily destroyed or lost when foods are preserved, stored, and cooked. With the current emphasis on highly refined and precooked convenience foods and the great distances fresh foods must travel before they reach the consumer’s table, the modern American diet may shortchange some people.

Much of the following advice on how to get the most vitamins for your food dollar is derived from research cited in Nutritional Evaluation of Food Processing.

Eat whole grain rather than refined breads and cereals and brown rice instead of white. Enriched breads, pasta, cereals, and rice are second best. Parboiled or converted rice has more vitamins than polished rice.

Use fresh or frozen fruits and vegetables instead of canned ones. During canning, the amount of many vitamins is reduced by half or more, and further losses occur during storage of the canned goods. Freezing, followed by storage and cooking, also reduces the vitamin content, but much less than does canning. Boil-in-the-bag frozen foods are preferred for their vitamin content. Don’t thaw frozen vegetables before cooking.

Storage of fresh foods in your refrigerator for one or more days leads to considerable vitamin loss. For those who cannot shop often, frozen fruits and vegetables may be as nutritious as the fresh. Foods that are frozen are picked ripe and processed rapidly, whereas days or weeks may elapse before fresh produce is consumed.

Fruits and vegetables ripened on the plant (except for pineapples) and in the sun have considerably more vitamin C than those picked green or grown in shade. To preserve vitamin C, fruit should be chilled immediately after being picked and kept cold and uncut until eaten. Most of the vitamin C in fruit is in and just under the skin, so paring fruit results in a considerable loss.

Avoid prolonged soaking of fresh vegetables, or you’ll wash the B vitamins and vitamin C down the drain.

Prepare salads just before they are to be eaten. Delay the cutting up and preparation of foods until shortly before they are to be cooked and eaten.

Keep all fresh, cut, and cooked foods well wrapped in the refrigerator.

In cooking vegetables, pressure cooking is least detrimental to vitamins. Steaming is second best. If boiling a vegetable, use as little water as possible – just enough so that nearly all is reabsorbed by the time the vegetable is done. Or use the cooking water, which will be rich in vitamins, in your recipe or to make a soup or stew.

Toasting bread destroys much of one of the B vitamins, thiamine. Bread crust has less thiamine than the soft crumb.

Potatoes baked in the skin retain most of their nutrients. Boiling potatoes in their skins is better than paring and cutting them up. In general, the more a vegetable is cut up before cooking, the greater the vitamin loss.

Glass, stain Jess steel, aluminum, enamel, and similar pots and pans do not affect nutrient content. But cooking in iron pots, an advantage to those who need extra iron in their diets, can destroy some of the vitamin C. So can unlined copper, brass, and monel (a nickel alloy). Copper also destroys folic acid and vitamin E.

Don’t cook vegetables with baking soda; it destroys thiamine and vitamin C.

Use the vitamin-rich syrup in canned fruits to make your own gelatin dessert. Make gravy from the defatted juices that drain from meats during thawing and cooking.

Riboflavin and vitamins A and D are readily decomposed by light. Keep milk and breads in opaque containers.

Buy milk and margarine that are fortified with vitamin A. Milk should also contain vitamin D.

Micronutrients: Essential in Tiny Amounts

smart review online — Thu, 22 Oct 2009 13:44:40 +0000

Micronutrients: Essential in Tiny Amounts

Throughout most of evolution, food was our only source of vitamins and minerals. Today, however, the “one-a-day” multivitamin-mineral tablet is a kind of nutritional insurance policy for millions of Americans, whether they need it or not. In recent years it has been eclipsed by megadose formulations of individual micro nutrients supposedly capable of performing health miracles far beyond warding off the well-known deficiency diseases.

The Lift Sustaining Vitamins

Even as millions down a veritable alphabet soup’s worth of vitamin supplements each day, confusion and controversy surround these nutrients. There’s only one fact about which there is no argument: Vitamins are essential to good health. But which ones, for whom, and how much?

Vitamins are organic substances that are required in the diet in tiny amounts – altogether, less than an eighth of a teaspoon a day – to assist in your body’s processing of other major nutrients, protein, fats, and carbohydrates. In addition, certain vitamins participate in the formation of blood cells, hormones, nervous system chemicals, and genetic material. Most vitamins function as aids to enzymes. When a particular vitamin is missing from the diet or is present in inadequate amounts, characteristic deficiency symptoms develop.

The amount of each vitamin that the federal government recommends for daily consumption is based on how much is required to avoid any signs of deficiency in the average person, plus a substantial safety margin to take into account natural variations in individual needs and abilities to absorb consumed vitamins. However, a number of circumstances, including cigarette smoking, the use of certain drugs, various illnesses, old age, heavy use of alcohol, and pregnancy and lactation may increase a person’s need for certain vitamins beyond ordinary recommended amounts.

Users of oral contraceptives, for example, need extra B vitamins thiamine, niacin, pyridoxine, and B12 – and vitamin C. Heavy smokers need additional C, and heavy drinkers require more thiamine, niacin, pyridoxine, and folic acid than other people, even if they eat otherwise good diets. The elderly tend to absorb less of the B vitamins and vitamin C and so may need to consume extra amounts. Persons with obstructive jaundice, bowel diseases, or chronic diarrhea may absorb little of vitamins A, D, E, and K. Prolonged use of antibiotics can destroy the intestinal bacteria that normally produce several of our B vitamins and vitamin K. Following surgery, illness, injury, or extensive bums, the body’s need for vitamin C is increased.

It is commonly asserted that anyone who eats a “well-balanced diet” doesn’t need additional vitamins. Such a diet is described as including, each day, at least four servings of grain and cereal products, four or more servings of a variety of fruits and vegetables, two servings of dairy products, and two of meat, fish, poultry, or protein-rich legumes. Although this particular balance of foods certainly does not offer the only way to consume adequate vitamins, it is considered a reasonable guide for the average person.

Obviously we all don’t eat this way. For some people, such as those who eat erratically, those on strict low-calorie diets, those who rely primarily on heavily processed and canned foods, picky eaters, and vegetarians, a diet containing adequate amounts of vitamins may not be consumed. In these cases supplementing the diet with a multivitamin pill may be advisable.

However, improving one’s diet is clearly the preferred route to obtaining essential nutrients, since there is no pill that can completely compensate for the deficiencies in an inadequate or poorly balanced diet. And don’t assume that you don’t have to worry about what else you eat because you start each day with a vitamin-packed cereal. You can’t be sure how many of the vitamins in your bowl actually get into your body, and no cereal contains all the required vitamins in the needed proportions.

If you do need a vitamin supplement, with the exception of vitamin E, it matters not (except to the income of the seller) whether you buy “natural” or synthetic vitamins. The body can’t tell them apart. A molecule of vitamin C (ascorbic acid) is the same whether it originated in a rose hip or a chemistry lab. For vitamin E, the natural form is chemically different and slightly more active than synthetic versions.

There are thirteen undisputed vitamins – four that are soluble in fat and nine that are soluble in water – plus one to five other substances (including choline and inositol) that some assert are vitamins but that others say are not, since they are produced in the body in adequate amounts and no deficiency symptoms are associated with their absence in the diet.

The fat-soluble vitamins – A, D, E, and K – are generally consumed along with fat-containing foods. They are absorbed through the intestines with the aid of bile produced by the liver or fats in the diet. Because they are stored in your body’s fat , they do not necessarily have to be consumed each day.

Thus, a cooked carrot every other day, a cup of spinach every five days, or two ounces of beef liver once a week can fulfill an adult’s need for vitamin A. But also because they are stored, there is a danger of overdosing yourself with fat-soluble vitamins.

Water-soluble vitamins – eight B vitamins and C – present the opposite problem. The body has no storage depot for most of them, and they are continually being washed out with urine and sweat. Therefore, they should be consumed daily in adequate amounts to meet the body’s needs.

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Keeping Vitamin Values Intact