January 26, 2007

Vitamins, inside and out

By Donna Lee, M.D.
Special to the Times

This article contains general medical information only; it is not a substitute for personal visits with your own physician. Since every patient’s situation is unique, please contact your personal physician for specific advice regarding your health.

Many of my patients ask me whether they should take vitamins, minerals, and other supplements. Here is some information to answer some of the more frequently asked questions I receive:

Multivitamins
It would be great if we all ate well-rounded diets and got the essential vitamins and minerals from natural food sources. But the reality is that we often don’t. I see multivitamins as inexpensive insurance for the days we don’t eat well. Most of the widely available national brands are similar; I have not seen any compelling reasons to buy the more expensive brands. There was some recent concern over lead found in one brand; this reminds us that since vitamins and supplements are not regulated by the FDA, we do need to be cautious about where we buy them. I tell my patients to look for the large manufacturers that have been in business for a long time.

Prenatal Vitamins
While multivitamins are optional for the general population, prenatal vitamins are very important for women who are pregnant or trying to get pregnant. Folate deficiency is a leading cause of neural tube defects such as anencephaly. These defects are minimized by consuming at least 800 micrograms of folate per day before and during pregnancy. Prenatal vitamins also have extra iron, which many women become deficient in during the third trimester.

Vitamin A
Most diets have adequate amounts of vitamin A, so I do not recommend oral supplementation to my patients. However, topical forms of vitamin A are a different story. Retin-A, a topical prescription form of vitamin A, is an antioxidant that can neutralize free radicals in the skin. This can reduce the appearance of wrinkles, sun damage, and uneven pigmentation. One recent study also showed it can reverse early skin cancers. Even though it is considered the “fountain of youth” for skin, it must be used with care since it can increase the skin’s reaction to the sun and to various skin treatments. Retinol, a non-prescription form of vitamin A, has varying results depending on formulation. Neither oral nor topical vitamin A should be used in pregnancy.

Vitamin C
Many people swear by high doses of vitamin C during colds, but the research has not been conclusive. Since it is water soluble, the kidneys can easily excrete the excess, and even high doses do not seem to be harmful. Vitamin C is also an antioxidant that can neutralize free radicals when applied to the skin. It also appears to stimulate collagen to reduce the appearance of wrinkles and scars. With vitamin C, the major issue is the degree of penetration into the skin and the stability of the molecule, which can vary greatly depending on formulation and packaging.

Vitamin E
Since vitamin E is also an antioxidant, researchers expected it to be beneficial to health. But a recent study actually showed increased risk of cancer and heart disease in patients who took high doses of vitamin E. After this study came out, it was hypothesized that the doses used were simply too high. But until more studies are done, I am not recommending extra vitamin E (on top of what a multivitamin might have) for my patients. Topical vitamin E is found in many skin care products, but many forms of it are either poorly absorbed into the skin or can cause irritation.

Coenzyme Q10
This is an antioxidant that also regulates energy production in cells. It is being researched as a treatment for heart failure, but studies have not been conclusive so far. It does seem to be helpful in counteracting some of the side effects of certain cholesterol or cancer medications. Idebenone, a topical form of coenzyme Q10, has been found to be the strongest topical antioxidant available, and may minimize the appearance of fine lines and improve skin texture.

Calcium
Many people do not consume enough dairy products to get the 1,000 mg of calcium that is recommended, so calcium supplementation is a good idea. Certain people, such as pregnant or breastfeeding women need even more. Vitamin D is required for calcium to be absorbed, and luckily, many supplements combine calcium with vitamin D. There was some confusing data uncovered by the Women’s Health Initiative recently, which showed that calcium supplementation did not prevent hip fractures in postmenopausal women. But this study was limited by two problems: 1) the women in the supplementation group missed their calcium tablets close to 40 percent of the time; 2) the women in the control group were not told to avoid calcium, and because of the noncompliance in the supplementation group, there was only a small difference in the amount of calcium that was actually ingested by the two groups.

The one basic thing that we do know about calcium is that it is required for muscles, especially heart muscle, to function, and if there is not enough in the diet, the parathyroid glands will steal the calcium out of the bones so it will be available for the other vital functions. This can lead to osteoporosis later in life.

Iron
This mineral is not indicated unless a person has iron deficiency anemia, a condition that requires a blood test to diagnose. When it is used to treat this disorder, periodic blood test are needed to prevent overdose, which can cause liver disease.

I hope this list answers some of the questions you may have had regarding vitamins and minerals. Please contact your primary care physician for more specific details regarding these or other supplements.

Dr. Lee is board certified in internal medicine and has recently moved her practice to Evergreen. She is also the medical director of Clarity Medical Spa. She has a special interest in cosmetic dermatology and patient education. Contact her office at (408) 270-3877 or visit www.claritymedicalspa.com.