Shopping for dietary supplements: how to purchase the best products

by Richard Glickman-Simon, MD

In the first article of this two-part series on shopping for dietary supplements (DS), we considered their safety and effectiveness. With that background, we can now tackle the vast and daunting DS market, step-by-step. Here is a guide to help you choose the safest and most effective supplements available.

Before you get started, make every effort to:

Obtain a diagnosis. Most DS research is based on clinical diagnoses (depression, for example) rather than symptoms (feeling down). Therefore, knowing what condition you wish to treat will make your DS decision more scientific, and likely more effective.

Know your options. To make an informed decision about any medical intervention, you need to learn about all your alternatives. What matters most is not the effectiveness of a DS for your condition, but how favorably it compares to other available treatments.

Consult your doctor. Your doctor shares responsibility for your overall health, therefore he or she needs to know about anything that may affect it whether its the job you have, the food you eat, or the dietary supplements you take.

You have an enormous array of DS products to choose from. Dozens of manufacturers market their wares in every imaginable form: tablets, capsules, extracts, tinctures, powders, teas, and nasal sprays. And on top of that, the quality of these products varies tremendously. Since DS are not regulated like medications, the government does not guarantee that a product you choose actually contains whats advertised on the label. So, how should you proceed?

Decide on a formulation. When studying DS, researchers prefer to use standardized concentrations so they know exactly what their subjects are receiving. This allows them to report their results in terms of the exact concentration of the substance of interest, usually the active ingredient, if this is known.

Therefore, if you choose to take a DS based on the scientific evidence, it makes sense to take it in the same formulation used in the studies. This does not mean that you cannot benefit from other forms. Your chances of success, however, will be greater if you choose highly standardized capsules or tablets rather then difficult-to-standardize tinctures or teas.

Determine a dose. Researchers also report at what dose a DS produces its effects �both intended and unintended. In order to achieve the desired outcomes while avoiding the undesirable ones, stick with the minimum dose reported.

More is not better. If the best studies show that 200 milligrams (mg) is effective, it does not mean that 400 mg is even more effective. This kind of thinking can be dangerous, since the risk of an adverse effect generally increases with the dose.

The opposite is also true. Taking less than the minimum effective dose is a waste of money. There is no evidence that the common practice of adding a dietary supplement to a food, for example, changes the health benefits of that product. The regular use of the herb ginkgo biloba may enhance short-term memory in elderly patients with dementia. This does not mean, however, that the sporadic consumption of a ginkgo-laced soft drink will have any effect on memory in anyone.

The Natural Health Encyclopedia provides information on formulations and doses for dozens of DS that have been scientifically investigated.

Once you have determined the best formulation and dose, your next decision is which brand to buy. Since the US government does not ensure standards of concentration accuracy and purity for DS, you must look to private laboratories that test various products already on the market. You can be reasonably sure that the products successfully passing their testing procedure are free of contaminants and contain what the label indicates.

Find a store that specializes in dietary supplements, since it probably hasmore to lose by selling low quality merchandise. This does not mean you can never find reliable products at a supermarket or pharmacy, but if you have questions youll more likely to get answers at a specialty retailer. There is no reason, however, to trust their opinion blindly. Arrive with the facts, then ask your questions.

Once you have selected a DS, take it as directed. While some supplements seem to work best when taken over short periods of time for intermittent symptoms (for example, Echinacea), most should be taken regularly for weeks or months at a time. In fact, many DS take that long to reach their maximum effectiveness. If you discontinue these supplements too early or take them intermittently, you will never know their true effects.

As soon as you begin taking a supplement, pay careful attention to any change in your symptoms and any new symptoms. All the research in the world cannot reliably predict who will respond to a DS and who will not. There is always some degree of trial and error, which is also true of medications. The only way to know if a DS if useful for you is to give it a try and carefully monitor its effects, both favorable and unfavorable.

Keep your doctor informed of your progress. This is particularly important if you are combining a DS with medications. Adverse interactions between DS and drugs are not uncommon, and it should be your doctors responsibility to protect you from them.

The vast majority of adverse effects associated with DS are reversible, but some of them may not show outward symptoms until the problem has progressed. If necessary, your doctor can watch for worrisome side effects even before they become symptomatic. He or she may also wish to adjust your other treatments depending on how well your DS is working.