Micronutrients Part I: Vitamins
Vitamins, minerals, antioxidants, and phytochemicals are called micronutrients because, in comparison with protein, carbohydrates, fats, and water, they are needed by the body in relatively small amounts.
But just because you only need a little doesn't mean they don't pack a punch. Without them you couldn't get the energy out of carbohydrates and fats, or transform the protein you eat into your own lean body mass.
Micronutrients have, of course, been in the food supply since the beginning of time. Vitamins and minerals, and their importance in disease prevention, were discovered in the early years of this century. Antioxidants and phytochemicals are only now being recognized as nutritional stars in the battle against cancer and in the nutritional management of HIV and other chronic diseases. Vitamins frequently have antioxidant properties, and minerals are part of antioxidant enzymes. And you will see that phytochemicals are food too.
What used to be called the RDA, or Recommended Daily Allowance, is now called the DV, or Daily Value. This is the average amount of individual nutrients recommended for consumption by "healthy" people in the United States.
According to the Food Guide Pyramid (which replaced the Basic Four Food Groups a few years ago) a healthy adult should eat six to eleven servings daily of carbohydrates (bread, rice, cereal, pasta), five to nine servings of fruits and vegetables, two to four of meat or vegetable protein, and two to three of dairy or soy milk products. All of these foods contain the micronutrients discussed in this article.
A well-balanced diet based on the Food Guide Pyramid provides 100 to 200 percent of the DV for some of the vitamins and minerals. Early research in nutrition and HIV showed that people who took a multivitamin with mineral supplement that provided 100 percent of the RDA did better than those who didn't take a supplement. So, by eating a good diet and taking a daily multivitamin with mineral supplement, you may be able to avoid a trip to the health food store for further supplementation. You be the judge!
Defining the MicronutrientsVitamins:
Thirteen vitamins have been discovered to date, and each has a specific function. Most vitamins come from the diet, but some are actually produced by the so-called "friendly bacteria" that live in your intestinal tract. The fat-soluble vitamins -- A, D, E, and K -- are for the most part absorbed with fatty foods in your body. They are stored in various tissues of the body and are not excreted in the urine. The water-soluble vitamins -- C and the Bs, including thiamin, niacin, riboflavin, folic acid, and B12 -- are not stored in the body but are excreted in the urine. Because they are not stored, there is less danger of toxicity from the water-soluble than from the fat-soluble vitamins.
In general, vitamins, regulate biochemical reactions in your body. They act like the key in the ignition of a car. Without them, the reactions can't get started. Some vitamins have antioxidant activity.
Minerals: To date, 21 minerals have been identified. They form the structures in the body, e.g., calcium in bone, iron in the blood, and they also regulate metabolic processes. Minerals also participate in antioxidation.
Antioxidants: These are the "free radical" scavengers. Free radicals damage cells, including T-cells, and are caused by infections such as HIV, smoking, bad fats, and pollutants such as exhaust fumes in the air. Antioxidants seem to consume free radicals, prevent disease, protect cells, and slow the aging process and the progression of HIV to AIDS. Some vitamins are antioxidants.
Phytochemicals: These are plant compounds, many of which are antioxidants, that seem to help prevent heart disease and cancer. Like antioxidants, they too protect cells. Many plants that contain phytochemicals are brightly colored, such as red tomatoes.
To help you decide how best to get the micronutrients you need, you need to know the function of each and where to find it in the food supply, how much is enough, and what can happen if you overdo it. This month's article will discuss vitamins, the largest category of micronutrients; minerals, antioxidants, and phytochemicals will be discussed next month.
The Fat-Soluble VitaminsVitamin A:
Vitamin A is essential for normal vision, growth and development, and a healthy immune system. The animal form of vitamin A is found in milk, liver, fish, cheese, butter, and eggs. In this form, vitamin A in excess is toxic and can cause nausea, vomiting, headache, bone and joint pain, and, in extreme cases, liver damage.
There is also a plant form of vitamin A called beta carotene. This form is water soluble and not toxic. With beta carotene you get two for the price of one: It converts to do all the things that vitamin A can do, without the toxicity, and it works as an antioxidant, protecting your cells. Foods rich in beta carotene include carrots, sweet potatoes, pumpkins, spinach, cantaloupe, and broccoli.
In the early days, before antiviral therapy, there was a study that suggested that beta carotene, as an antioxidant, might be helpful in combating HIV because it seemed to increase the T-cell count. The results were published after only eight weeks of this study, and long-term follow-up has not been as promising.
Other studies looking at lung cancer prevention in smokers have shown that those taking beta carotene supplements had a higher incidence of the cancer. It is thought that the problem is that large amounts of beta carotene block the use of other carotenoids (phytochemicals in food that are similar to beta carotene, but without the vitamin A activity) that may be more potent against cancer. The bottom line is, take your multivitamin, and eat more of the brightly colored fruits and veggies that are high in beta carotene and other carotenoids. Your best bet is to eat lots of fruits and vegetables of every color every day.
Vitamin D: Vitamin D is essential for healthy bones. It helps you absorb the mineral calcium, which you need for healthy bones, from the food you eat. Vitamin D is found in milk, liver, fish, and eggs. It is called the "sunshine vitamin" because it is manufactured in the skin when it is exposed to the sun's rays.
Like vitamin A, vitamin D is toxic in excess because it is stored in the body. Too much vitamin D can cause calcium deposits in soft tissues, such as the kidney and lung. Except for what is contained in a standard multivitamin with mineral supplement, vitamin D supplements should be taken with caution.
Vitamin K: This vitamin is essential for blood clotting. Found primarily in green leafy vegetables, with lesser amounts in egg yolks, liver, and whole wheat, vitamin K is also synthesized by friendly bacteria in the intestine. Deficiency is rare, but can be induced by prolonged antibiotic therapy that destroys the good as well as the bad bacteria in the intestinal tract. Liver disease also interferes with vitamin K use and usually requires supplementation. Because of the potential for toxicity, single vitamin K supplements are available only by prescription.
Vitamin E: Vitamin E has antioxidant activity and affects muscle development, neurological function, and immune system integrity. A deficiency can cause peripheral neuropathy and hemolytic anemia. As an antioxidant, E is a component of cell membranes and protects the cell from free radical damage and destruction, thereby protecting against aging, cancer, and other degenerative diseases. Vitamin E has been shown to increase cell-mediated immunity in healthy elderly people. This is the same kind of immune function that is impaired in HIV disease. E has also been shown to prevent heart disease and cancer, and it slows the progression of Alzheimer's and Parkinson's disease and improves memory.
Vitamin E increases the anti-HIV activity of AZT and reduces that drug's bone marrow toxicity. Studies of vitamin E along with vitamin C have found reversal of the muscle damage caused by AZT. Keep in mind that your Combivir contains AZT.
E is the only fat-soluble vitamin that appears relatively nontoxic. Most studies of the vitamin have used 800 IUs (International Units) with no ill effects. Given the unknowns with the antiretrovirals, however, such large dosage might be dangerous for people with HIV. Good food sources of vitamin E are vegetable oils, fish oils, nuts, whole grains, wheat germ, soy, green leafy vegetables, and avocados. When buying supplements, this is the one case where natural clearly beats synthetic; it's better absorbed. If you're in the market, look for d-alpha tocopherol, or the new RRR-alpha.
CAUTION: If you are using aspirin, gingko biloba, or prescription blood thinners, or if you have problems with blood coagulation, thrombocytopenia, diabetes, or rheumatic heart disease, stay with the DV, which is 30 IUs. Among its many attributes, vitamin E thins the blood (this is how it protects against heart attacks and strokes). If you have high blood pressure, as your doctor. Vitamin E may increase the risk of stroke.
The Water-Soluble VitaminsVitamin C:
This is a water-soluble vitamin with antioxidant properties. C's most important role is synthesizing collagen, the building block of new tissue. When we get a wound, we need C to heal. It assists in the absorption of the mineral iron, the activation of the vitamin folic acid, the conversion of the amino acid tryptophan to the neurotransmitter serotonin, and the synthesis of the amino acid carnitine from dietary amino acids. It enhances immunity and lessens the severity and duration of the common cold.
As an antioxidant, vitamin C is being studied in the prevention of cataracts and the age-related macular degeneration that often results in blindness. Vitamin C may have a role in the prevention of heart disease. It may raise levels of the good cholesterol (HDL) and prevent oxidation of the bad cholesterol (LDL). Oxidation is damage to the molecule that makes it more dangerous, increasing the risk of buildup inside the artery and of heart disease. Vitamin C may also be useful in the fight against gastrointestinal cancer.
Early work on C's anti-HIV effect at the Linus Pauling Institute indicated that in the test tube it effectively decreased virus production by working on the reverse transcriptase enzyme, the same enzyme inhibited by the AZT-type drugs. Studies in humans are lacking.
Good food sources of vitamin C are citrus, berries, kiwis, green leafy vegetables, cantaloupe, mango, peppers, and tomatoes. There is vitamin C in most other fruits and vegetables as well, but in varying amounts. Vitamin C dissipates quickly when cut veggies and fruits are exposed to oxygen, and the loss is accelerated when the foods are exposed to light and heat. Cooking causes the foods to lose half their vitamin C. Vegetables should be eaten raw or lightly steamed; if you cook them, use only a small amount of water.
If you don't eat fruits and vegetables, you may want to consider supplementation of vitamin C in addition to your multivitamin. The general recommendation is 500 to 1,000 mg per day. If you smoke, go up to 1,500 mg. Unlike vitamin E, synthetic forms of C are equally as effective and potent as the natural forms.
CAUTION: High doses of C may cause stomach upset or diarrhea. Buffered C may relieve the stomach upset. If you have diarrhea, cut back. If you decide to stop taking vitamin C, cut back slowly. There is a phenomenon called "rebound scurvy," a form of the vitamin C deficiency disease that happens when you stop too quickly. It consists of poor wound healing, loose teeth, loss of hair, and dry itchy skin.
Another cautionary note regarding vitamin C is that it promotes the absorption of dietary iron. If you are at risk for iron overload disease (hematochromatosis), do not take vitamin C supplements, or even a multivitamin that contains vitamin C or iron. Iron will be discussed in detail in next month's article dealing with minerals.
The B Vitamins: These include thiamin, riboflavin, pyridoxine, folic acid, and B12. They are frequently lumped together because they work together in the body and are frequently found in the same foods. If you have a deficiency of one, you are likely to have problems with the others. Vitamin supplements commonly called B complex also give you the full range of these vitamins in a single unit. Alcohol use can cause uniform B vitamin deficiency. This review of the B vitamins takes into account only those that are significant for their role in HIV disease.
Thiamin (B1), riboflavin (B2), pyridoxine (B6), folate, and vitamin B12 are used as coenzymes in all parts of the body. They participate in the metabolism of fats, carbohydrates, and proteins. They are important for the structure and function of the nervous system. They have a synergistic effect; that is, they help each other. Riboflavin, for example, is needed to convert B6 to its active form. Low folate levels can contribute to thiamin deficiency.
Thiamin is found in red meat, whole grains, peas, beans, nuts, and yeast. Deficiency can result in weight loss, poor appetite, peripheral neuropathy, and, in extreme cases, changes in mental status.
Riboflavin is found in enriched whole-grain products, dairy products, meat, fish, and green leafy vegetables. Deficiency can cause burning and itching of the eyes, tongue and mouth pain, anemia, and personality changes. Compazine, used for nausea, and Elavil, used for HIV neuropathy, can result in drug-induced deficiency.
Pyridoxine (B6) is found in meat, fish, egg yolks, beans, fruits, vegetables, and whole grains. Symptoms of deficiency include irritability, depression, skin rashes, peripheral neuropathy, tongue and mouth tenderness, and, in extreme cases, seizures. B6 deficiency also affects the immune system adversely. Isoniazid (INH), the drug used to treat tuberculosis, depletes B6 levels. You need a daily dose of 50 mg of B6 if you are taking INH.
CAUTION: High-dose B6 (more than 1 gram per month) can cause numbness, lack of muscle coordination, or paralysis.
Folate is found in meat, deep green leafy vegetables, broccoli, oranges, wheat bran, legumes, and enriched cereals. Deficiency can cause anemia, neurological symptoms, and fatigue. Neural tube birth defect is the classic folic acid deficiency that affects newborns of folate-deficiency mothers. Bactrim blocks folate, and AZT depletes folate levels. Birth control pills seem to cause a localized folate deficiency of the cervix.
In addition to its shared role with the other Bs, folic acid is a star in its own right in the battle against heart disease, colon cancer, and cervical cancer. Because of the urgency and critical nature of folic acid deficiency in pregnancy, the FDA has mandated that manufacturers of breads, flours, cornmeal, farina, rice, noodles, and breakfast cereals fortify their foods with folic acid. Look for the nutrition information on the label.
Vitamin B12 is found mostly in foods of animal origin, including beef, herring, egg yolk, milk cheese, shellfish, and sardines. It is also found in tempeh (fermented soy food). The classic deficiency disease is pernicious anemia, most often seen in alcoholics and strict vegetarians. Deficiency can also cause nerve damage, peripheral neuropathy, depression and psychosis.
People with HIV and AIDS may be B12 deficient for many reasons: The substance in the stomach needed for B12 absorption needs an acidic stomach, and some people with HIV and AIDS take antacids, such as Mylanta and Prilosec, to neutralize the acids that cause their chronic stomach irritations. Also, vitamin B12 is one of those vitamins that is synthesized in the colon by the friendly bacteria (this may be its best source), and chronic antibiotic use can destroy these bacteria and eliminate that resource.
The big problem with B12 and HIV is that the standard tests for B12 serum levels may register normal even though you have a deficiency. More sophisticated tests are not available to the medical community in general, but are used in research. The studies indicate that about 10 to 27 percent of people with HIV are B12 deficient. Separate studies show peripheral neuropathy and myelopathy, diminished problem-solving skills, CD4-cell decline, increased AZT-related bone marrow toxicity, and increased progression to AIDS and mortality.
Notes on the Bs as Foods: Foods like white rice -- which has been stripped of the outer layer that includes the B vitamins, bran, and germ -- must be enriched with the B vitamins that were removed. If you tend to wash rice before you cook it, that white stuff that comes off is the vitamins. Don't wash it, or better yet, buy brown rice. All the vitamins are there with the fiber naturally. Most of the major cereal companies, like Kellogg's and Post, fortify breakfast cereals with B vitamins. This offers a substantial dose and really does help meet the body's requirements.
All foods lose their vitamin potency when heated or exposed to light. Meat loses from 25 to 40 percent of its vitamins during cooking. Milk stored in clear glass bottles loses up to 75 percent of riboflavin in three hours. When bread is baked, it loses from 15 to 20 percent of the thiamin during the process. It is estimated that 68 percent of the folic acid in wheat is removed when it is processed into white flour.
Folate found in food is only half as efficient as the folic acid found in supplements and fortified foods. Add to that the losses in cooking, and if you don't get a really wide variety of folate foods, both raw and cooked, a supplement is in order.
If you have neuropathy, a vitamin B complex daily and a monthly B 12 injection are a good idea. If your doctor won't give you the shot, try megadosing at 1,000 ug orally. It can't hurt, and it might help. B12 is not toxic.
Whether you decide to supplement individual vitamins or to stick with a balanced diet and a multivitamin with minerals, be sure to talk to your doctor. It's important that your primary care physician knows what you are eating, what you are taking, and what you are doing.
This article was provided by Body Positive. It is a part of the publication Body Positive.