Anti-Aging Health

The Science of How to Choose the Best Supplements

By Kim Crawford, M.D. Last updated: September 6, 2018
how to choose the best supplements

How to choose the best Vitamins, Supplements, and “Integratives”

Are you eating enough fruits and veggies? If not, maybe you’re considering a “one-a-day.” Perhaps, your energy levels are low, and you think a good handful of supplements for energy will help. Well, do you know how to choose the best supplements? The safest? The most effective? Before spending your money on possibly ineffective (at best) and (at worst) toxic products, read this information. In this article, I’ll reveal in detail the facts, so you’ll know exactly how to choose vitamins and supplements. You’ll even know how to choose “integratives” which is a fancy term for supplements that can help with medical issues. Let’s begin with the basics.

The Basics of Knowing What You’re Taking

As defined by Congress in the Dietary Supplement Health and Education Act, which became law in 1994, a dietary supplement is a product (other than tobacco) that is intended to supplement the diet. So far, so good? It contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances) or their constituents. That makes sense too, right? It is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and is labeled as a dietary supplement. That is a supplement; Let’s discuss how it differs from foods and drugs.

Are dietary supplements different from foods and drugs?

Although the FDA regulates dietary supplements as foods, they are regulated differently from other foods and drugs. Whether a product is classified as a dietary supplement, conventional food, or drug is based on its intended use. Most often, classification as a dietary supplement depends on the information the manufacturer provides on the product label or in accompanying literature. However, many foods and dietary supplement product labels do not include this information. This is your “buyer beware” warning. Let’s talk about manufacturers’ claims.

What claims can manufacturers make for dietary supplements and drugs and how do they differ?

The types of claims on the labels of dietary supplements and drugs do differ. Drug manufacturers may claim their product will diagnose, cure, mitigate, treat, or prevent a disease. Such claims may not legally be made for dietary supplements by the manufacturers. Please note when I write about inflammation or oxidative stress (as examples), these are not diseases per se. However, a life of high inflammation and oxidative stress will indeed cause disease.

The label of a dietary supplement or food product may contain one of three types of claims: a health claim, nutrient content claim, or structure/function claim.

Health claims describe a relationship between a food, food component, or dietary supplement ingredient, and reducing the risk of a disease or health related condition.

Nutrient content claims describe the relative amount of a nutrient or dietary substance in a product.

A structure/function claim is a statement describing how a product may affect the organs or systems of the body and it cannot mention any specific disease. Structure/function claims do not require FDA approval. However, the manufacturer must provide the text of the claim to the FDA within 30 days of putting the product on the market. Product labels containing such claims must also include a disclaimer that reads, “This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.” So, what role does the FDA play?

How does the FDA regulate dietary supplements?

In addition to monitoring label claims, the FDA regulates dietary supplements in other ways. Supplement ingredients sold in the United States before October 15, 1994, are not required to be reviewed by FDA for their safety before they are marketed because they are presumed to be safe based on their history of use by humans. For a new dietary ingredient (one not sold as a dietary supplement before 1994) the manufacturer must notify the FDA of its intent to market a dietary supplement containing the new dietary ingredient. The manufacturer also must provide information conveying that reasonable evidence exists for safe human use of the product.

The FDA can then either refuse to allow new ingredients into the marketplace or remove existing ingredients from the marketplace for safety reasons. Unlike drug products, there are no provisions in the law for the FDA to “approve” dietary supplements for safety or effectiveness before they reach the consumer. Once a dietary supplement is marketed, the FDA has to prove the product is not safe to restrict its use or remove it from the market.

In contrast, before being allowed to market a drug product, manufacturers must obtain FDA approval by providing convincing evidence that it is both safe and effective. For this reason, you must know how to read labels.

What about labeling?

The label of a dietary supplement product must be truthful and not misleading.

Ingredients and nutritional information are supposedly “accurate.” It is up to the manufacturers here to a large extent. If the label does not meet this requirement, FDA might remove the product from the marketplace or take other appropriate actions. A report in the New York Times revealed testing by the N.Y. State’s Attorney General’s office which found severe flaws in supplements sold at GNC, Walmart, Target, and Walgreens. Please do read the details of the labeling process.

I want you to understand buying OTC supplements is very risky. Contaminants, toxins, and “not what is on the label” are common. The same type of “nasty” findings have also occurred with many brands including the popular Life Extension brand as well. If you purchase from a known, certified, trusted source, you’ll be fine. I’ll tell you how to determine that next.

What information does a dietary supplement label require?

The FDA requires that certain information appears on the dietary supplement label. Here are the general labeling laws:                 

1. Name of product (including the word “supplement” or a statement that the product is a supplement)
2. Net quantity of contents
3. Name and place of business of manufacturer, packer, or distributor
4. Directions for use

The label needs to list the serving size, list of dietary ingredients, the amount per serving size (by weight), and percent of Daily Value (%DV), if established. If the dietary ingredient is a botanical, the scientific name of the plant or the common or usual name standardized in the reference Herbs of Commerce, 2nd Edition (2000 edition) and the name of the plant part used must be listed. If the dietary ingredient is a proprietary blend (i.e., a blend exclusive to the manufacturer), the total weight of the blend and the components of the blend in order of predominance by weight must be listed. Nondietary ingredients such as fillers, artificial colors, sweeteners, flavors, or binders must be listed by weight in descending order of predominance and by common name or proprietary blend.

Caution Statements and Warning Signs

The label of the supplement may contain a cautionary statement, but the lack of a cautionary statement does not mean there are no adverse effects with the product. You may not be aware of ill effects as they might be due to toxins which build up over time. Again, for this reason, it is extremely important to purchase correctly. Note that one area of great concern where many violations take place are in the weight loss and energy sectors. A product may claim to be a natural appetite suppressant and contain stimulants! Vitamins for energy and supplements for energy are even worse. Brain boosting supplements may be dangerous racetam nootropics. Be careful when purchasing in these categories—I have many articles here to teach you what you might need.

Here’s a big warning sign: If you see all sorts of “junk” on a label, then it is junk. No artificial dyes, sweeteners (other than what I recommend) should hit your GI tract. Another red flag is the lack of a non-GMO label. Fillers are generally GMO-cornstarch if you do not see a non-GMO sticker on your supplements. You don’t want anything that is GMO (definition: full of pesticide residue) hitting your GI tract. Many experts think all of the GMO products “out there” are contributing to the national epidemic of leaky gut. I’m one of them.

How to Choose the Best Supplements for Your Health

Does a label indicate the quality of a dietary supplement product?

Mostly, yes.

how to choose the best supplements
In 2007, the FDA issued Good Manufacturing Practices (GMP) for dietary supplements; a set of requirements and expectations by which dietary supplements must be manufactured, prepared and stored to ensure quality.

The FDA expects manufacturers to guarantee the identity, purity, strength, and composition of their dietary supplements. For example, the GMP aims to prevent the inclusion of the wrong ingredients, the addition of too much/little of a dietary ingredient, the possibility of contamination and the improper packaging and labeling of a product.

This means if you are taking a supplement without a GMP label (please look!), you are not getting what the label says, and you might be getting things like heavy metals, talc and who knows what else! Notice that all products on this website carry a GMP and NSF certification. Next, let’s touch on standardization.

Are dietary supplements standardized?

Standardization is a process that manufacturers may use to ensure batch-to-batch consistency of their products. In some cases, standardization involves identifying specific chemicals (known as markers) that can be used to manufacture a consistent product. The standardization process can also provide a measure of quality control. The United States does not require standardization of dietary supplements.

In fact, no legal or regulatory definition exists in the United States for standardization as it applies to dietary supplements. Due to this, the term “standardization” may mean many different things. Some manufacturers misuse the term standardization to refer to uniform manufacturing practices; following a recipe is not sufficient for a product to be called standardized. Therefore, the presence of the word “standardized” on a supplement label does not necessarily indicate product quality. Then again, it might.

What methods are necessary to evaluate the health benefits and safety of a dietary supplement?

Federal law does not require testing of dietary supplements for safety and effectiveness before marketing the product. As a result, the amount of scientific evidence available for various supplement ingredients varies widely. Some ingredients in dietary supplements go through an evaluation. For example, scientists know that calcium, Magnesium, and vitamin D are important for keeping bones strong and reducing bone loss. Amino acids such as acetyl-l-carnitine have proven they increase energy by lessening mitochondrial dysfunction.

Other supplements, such as some herbal products, need more study to determine their value. Scientists can use several approaches to evaluate dietary supplements for their potential health benefits and risks. They may investigate the history of use, conduct laboratory studies using cell or tissue cultures, and experiment with animals. Studies on people (e.g., individual case reports, observational studies, and clinical trials) provide the most direct evidence of a dietary supplement’s effects on health and patterns of use.

Please note that all products sold by AgeWell are not only GMP compliant, but the standardization method is the same as is used in the pharmaceutical industry. That is what the NSF “seal” is.

how to choose vitamins and supplements

The GMP-NSF supplements are often called “pharmaceutical grade” which is a notch better than only GMP compliant. Yes, I know this is more than most of you “need to know,” but now all the answers are here in one place! Happy, safe supplementing!



  1. OH MAN with the GMO stuff now!

  2. Great info especially the GMO stuff!

  3. Gnc should go outta bz

  4. Wow-so complete- thanks for all this info. Now I know how to spend my money wisely!

  5. Great info! Never knew the GMO filler thing. Ugh!

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