Many older adults regularly take vitamins, minerals and other dietary supplements. But just because something is "natural" or "drug free" doesn't mean that it's always safe. As a senior, if you take any sort of supplement, you need to be aware of the risks and be sure to take the right dosage.

Your Daily Multivitamin

Most doctors agree that taking a daily multivitamin with minerals is good insurance against those times when you can't eat as well as you should. Doctors often also recommend daily multis to people older than age 50 because the ability to absorb some nutrients in food, such as the B vitamins, declines as people get older. Your doctor may also recommend specific B vitamins, such as B-12, in addition to a multivitamin, if he/ she thinks you need it. Check for a good brand on or ask your pharmacist.

Also look for a formulation designed for the nutritional needs of older adults. These multis generally contain the same amounts of vitamins A, C, D, E and K as those formulated for younger adults, but may contain higher amounts of the B vitamins. Multis made for seniors may also contain some ingredients that are helpful for older adults, such as lutein and zeaxanthin they can help prevent sight-robbing age-related macular degeneration) and lycopene (which may be helpful for preventing prostate cancer).

Important: Your multivitamin should not contain iron. Even without taking supplements, older adults can start to build up higher than normal levels of iron in their bodies. This isn't an issue for most people. But, if you have the hereditary disease hemochromatosis (iron overload disease), iron builds up in the body to dangerously high levels. You may not find that you have this disease until you start to exhibit serious symptoms, such as liver problems or diabetes, because there is no direct test for it.

Bottom line: Take an iron supplement only if your doctor tells you to for a specific reason.

Dosage: Doubling up on your daily multivitamin probably won't hurt-but it probably won't give you any extra benefit. Get more of the vitamins and minerals that are in your daily supplement, as well as extra fiber, antioxidants and other valuable nutrients, by adding more whole grains, fresh fruits and vegetables to your diet.


Most daily multivitamin supplements contain from 100 milligrams (mg) to 300 mg of calcium—considerably less than the recommended daily intake of 1,200 mg for men and women older than age 50. If you can't get the additional calcium from your diet (dairy products, sardines and spinach are good sources), consider taking calcium and vitamins D and K-all nutrients you need to maintain strong bones.

One good choice: Viactiv, which combines all three nutrients

Interaction caution: If you're taking a cycline antibiotic (tetracycline, doxycycline, etc.) or the antibiotic ciprofloxacin (Cipro), skip the calcium supplements until you finish the course of antibiotics-calcium blocks your absorption of the drug. You can continue taking a daily multivitamin while on a course of antibiotics, but take the drug and the multi several hours apart.

Dosage: 1,000 to 1,500 mg a day of calcium is safe for most people. More than that can cause constipation and could interfere with prescription medications. Calcium in the form of calcium carbonate is effective—and inexpensive. When taking calcium, take a total of 500 mg of magnesium daily for proper calcium absorption. And, be sure to get the recommended dietary allowance of vitamin D (400 IU) and the daily adequate intake of vitamin K (90 mcg for women, 120 mcg for men).

Herb Cautions

Herbal supplements should be used with caution at any age, but there are some herbs that can be especially dangerous for older adults…

  • St. John's-wort. Also called hypericum, this herb is usually taken at a dosage of 900 mg to 1,800 mg daily, and can help mild depression

Problem: It can interact badly with a number of drugs commonly prescribed for older adults, including blood thinners and medications for depression, epilepsy, Parkinson's disease, heart disease-even heartburn.

What to do: Because the list of drugs that interact with St.-John's-wort keeps growing, don't take it if you take any prescription drug. If you think you might benefit from treatment for depression, ask your doctor what will be the best course of action.

  • Ginkgo biloba can help age-related memory problems by improving blood flow to the brain.

Beware: Ginkgo biloba is a mild blood thinner. Don't use it at all if you take a prescription blood thinner, such as warfarin (Coumadin). If you take a daily low-dose aspirin, you can use ginkgo, but take it 12 hours apart from the aspirin. If you take a daily regular dose aspirin, ask your doctor about taking ginkgo.

Dosage: All reputable brands are standardized to contain 24% of flavonoids (chemical compounds with antioxidant properties). The usual dose is 60 mg, taken one to three times a day. Take with meals to avoid stomach upset.

  • Ginseng. Ginseng is an adaptogen, a naturally occurring substance found in plants that helps strengthen your body's ability to handle stress and fight off illness. Ginseng is especially helpful as you grow older. Studies have shown that ginseng can improve thinking and learning.

Side effects: Ginseng can lower blood sugar, which could be a problem if you take medication for diabetes. Ginseng can also cause headaches-stop taking it if that happens.

Quality caution: Be sure to use only American ginseng root (Panax quinquefolius), which is the species that has been most thoroughly studied and is believed by herbal practitioners to be most effective, and select a product from a well-known, brand-name manufacturer

Dosage: Ginseng is traditionally made into a tea-have no more than one cup a day. If you prefer capsules, stick to no more than 100 mg a day. Start with a low dose-half a cup of tea or 50 mg in capsule form. If you don't notice any negative effects, such as itching, skin rash, diarrhea or insomnia, gradually increase the daily dose to one full cup or 100 mg over a week's time.

  • Saw palmetto helps relieve symptoms of benign prostatic hyperplasia (BPH), also called enlarged prostate. Check with your doctor to be sure that your symptoms (frequent urination or difficulty urinating) aren't caused by something more serious.

Interaction cautions: Do not take saw palmetto if you're taking any prescription drug to relieve the symptoms of BPH, such as finasteride (Proscar or tamsulosin (Flomax), Saw palmetto lower levels of testosterone, as do the drugs, and levels may get lowered too much. Don't use saw palmetto if you take a blood-thinning drug such as warfarin. (Saw Palmetto is safe to take with a daily aspirin.)

Quality caution: Saw Palmetto products vary in quality, so look for a product from a well-known manufacturer.

Dosage: 320 mg daily.

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