Thursday, January 21, 2010

Food and Health: The Truth About Vitamins & Supplements

The Truth About Vitamins and their Supplements 

      All Photos courtesy of Wikipedia

      Researching for this topic, I found lots and lots of issues on whether to use higher levels of vitamins which they say are necessary for optimum health and issues on whether to use supplements as a source of additional vitamins.

     According to Vitamins & Health Supplements Online, Vitamins are a group of organic food substances or nutrients found only in living things--plants and animals. They have no calories and are not energy sources but they assist in metabolizing nutrients in food and necessary in keeping our bodies running smoothly. They are required to do many things and their excess and depletion can lead to acute and chronic diseases.

     Whereas before, the American Medical Association (AMA), according to anti-aging, has advised Americans to get their nutrients from food rather than pills, they published their new position in JAMA (the Journal of AMA) in Aug. 31, 2002 urging them to take multivitamin at least one a day. Their reason: 80% of Americans do not eat at least 5 helpings of fruit and vegetables per day which is the recommended minimum amount believed to provide sufficient essential nutrients. They said that a review of 9 vitamins have shown that elderly people, vegans, alcohol-dependent individuals and patients with malabsorption are at higher risk of inadequate intake. In addition to these, according to the General Conference of Nutritional Council (NADHealth website), premature babies, persons on very low reducing diet, pregnant women, women with excessive menstrual bleeding, heavy smokers, others whose nutrients are altered by medications and illness are also among those who have the risk of vitamin deficiency. According to JAMA, Jan. 18, 2010, vitamin deficiencies (extremely low levels) and even poor intake of some vitamins can affect resistance to infections, risk of birth defects, and risk of diseases such as cancer, heart disease, and osteoporosis (thinning of the bones). On the other hand, too much of certain vitamins, especially A and D, results in toxicity which causes bad effects such as headaches, nausea and diarrhea. JAMA added that the 'best way to take vitamins is from whole foods--fruits, grains, vegetables, dairy products and lean meats. However, taking multivitamin supplements will also ensure adequate amounts of the important vitamins'.

     Vitamins are divided into two classes (according to Wikipedia): Fat-soluble vitamins are absorbed through the intestinal tract with the help of lipids (fat) and more likely to accumulate in the body, therefore may likely lead to hypervitaminosis. Water-soluble vitamins dissolve easily in water and readily excreted from the body, therefore not readily stored. Consistent intake is important. Based on several references (those already mentioned plus Natl. Institute of Health, article by Dr. Mehmet Oz and his article in regarding Key Vitamins for Healthier Functions), I have enumerated below these vitamins, some of their functions, sources in food, RDA (Recommended Dietary Allowance is the average dietary nutrient intake level to meet the nutrient requirements of nearly all 97-98% healthy individuals), and the Recommended Optimal intake by Dr. Mehmet Oz

A. Fat-Soluble Vitamins

Vit. A     -vision, bone growth, cell reproduction, regulate immune system, skin health
             - Sources: in animals in the form of Retinol-liver, whole milk, fortified food products, cheese
                             in plants, most common form is Beta-carotene-carrots, spinach, cantaloupe, apricot, 
                                papaya, mango, squash, dark leafy vegetables
             -RDA      : for adults 2670 IU/day (International Unit)
             -Recommended Optimum intake: more than 1250IU, 2x a day is too much unless you have an eye 
Vit. D    - for proper absorption of calcium
            - Sources: sunshine, milk and fatty fish, egg yolk
            - RDA     : adults, 200 IU/day

            - Recommended Optimum intake: 500 IU/day, 2x a day

Vit. E    - antioxidant, cellular respiration
            - Sources: food in the germ of a seed or grain--wheat germ oil, nuts, whole grain, egg yolk
            - RDA     : 14 years +, 15 mg. or 22.4 IU/day
            - Recommended Optimum intake: 200 IU, 2x a day

Vit. K    - blood clotting, bone formation
            - Sources: broccoli, brussel sprouts, cabbage, cauliflower, kale, spinach, & soybeans
            - RDA     : 80 mg./day for male; 65 mg./day for female (adults)
            - Recommended Optimum intake: We can get enough from a normal diet.

B. Water-Soluble Vitamins

Vit. B1 (Thiamin) - energy process, aids the nervous system & functions of impt. enzymes, protein metabolism
            - Sources: in fortified breads, cereals, pasta, whole grains, lean meats(esp. pork), fish, dried beans
            - RDA     : 1.1 mg. /day for adult male; 0.8 mg./day for adult female
            - Recommended Optimum intake: 12.5 mg, 2x a day

Vit. B2 (Riboflavin) -energy production, wound healing, activates other B vitamins
           - Sources: organ meats(liver, kidneys, heart), almonds, mushrooms, whole grain, soybeans, green leafy 
           - RDA     : 1.7 mg/day for adult male; 1.3 mg/day for adult female
           - Recommended Optimum intake: 12.5 mg, 2x a day

Vit. B3 (Niacin) -energy process, proper digestion
           - Sources: dairy products as milk, poultry, fish, lean meats, eggs, whole meal flour
           - RDA     : 19 mg./day for adult male; 13 mg./day for adult female 
           - Recommended Optimum intake: at least 15 mg., 2x a day

Vit. B6 (Pyridoxine) - energy process, antibody formation
           - Sources: white meat (poultry and fish), bananas, liver, whole grain breads & cereals, soybeans
           - RDA     : 2 mg/day for male adult; 1.6 mg./day for adult women

           - Recommended Optimum intake: 2 mg., 2x a day

Vit. B5 (Pantothenic Acid) - energy process, essential for human growth, reproduction, manufactures antibodies and produces  Vit. D 
          - Sources: eggs, yeast, liver, cheese, peanuts
          - RDA     : 4-7 mg/day for adults
          - Recommended Optimum intake: 150 mg., 2x a day

Biotin (Vit. B7) -energy process, blood sugar regulation
          - Sources: egg yolks, oat meal, soy, mushrooms, peanuts, bananas
          - RDA     : 30-100 mcg.(micrograms)/day
          - Recommended Optimum intake: 150 mcg., 2x a day

Vit. B12 (Cyanocobalamin) - red blood cell formation, energy process, nervous system functions
          - Sources: meat, fish, poultry, eggs and dairy products
          - RDA     : 2.4 mcg./day for 14 years +
          - Recommended Optimum intake: 800 mcg./ day

Folic Acid (Folate, Vit. B9) -red blood cell formation, RNA & DNA synthesis, protein production
          - Sources: green leafy vegetables, beans, citrus fruits, beets, wheat germ and meat
          - RDA     : 400 mcg./day for adults; 600mcg./day for pregnant women; 500 mcg/day for nursing women

          - Recommended Optimum intake : 200 mcg., 2x a day 

Vit. C (Ascorbic Acid) - antioxidant, collagen synthesis, anti-viral, helps build tissues, strengthen immune system
           - Sources: cabbage, green leafy vegetables, citrus fruits
           - RDA     : 75 mg/ day for non-smoking women; 90 mg/day for non-smoking men; 110 mg/day for 
                    female smokers; 125 mg/day for male smokers
           - Recommended Optimum intake: 250 mg., 2x a day
        - According to JAMA, there is no convincing evidence to show that taking large amounts of Vit. C supplements improve health or ward off illness such as colds. Therefore, they emphasized that whenever possible, Vit. C should come from fruits and vegetables by eating 5 servings/ day.



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