Frequently Asked Questions about Dr Lewis Nutrition™, Dietary Supplements, Health, and Science

How is Dr Lewis Nutrition™ different from other dietary supplement companies?

Dr Lewis Nutrition™ prides itself on being an evidence-based, science-driven company. Whereas most dietary supplement companies have little to no history of primary involvement in research and development, our company is founded by a scientist who has spent the better part of his career to date conducting the studies that support our formulas. The culmination of our work is a targeted catalog of products based on statistically and clinically significant studies that have been published in peer-reviewed journals. Thus, Dr Lewis Nutrition™ assures you that we will only sell products that we have thoroughly evaluated by our team as part of a rigorous scientific process, a business model that is unique and mostly unequaled in this industry.

What is a dietary supplement?

A dietary supplement is a product that is intended to supplement the diet and contains one or more dietary ingredients: (1) macronutrients, i.e., carbohydrates, amino acids, or fatty acids, (2) vitamins and minerals, (3) herbs or other botanicals, or (4) other dietary substances. It also is intended to be taken by mouth, so it cannot be injected or given by intravenous infusion, which would constitute a drug. It cannot be represented as a conventional food or sole item of a meal or the diet. Companies who sell dietary supplements are prohibited from making a drug claim about their products (e.g., claims to cure or treat a disease). For more information, see the Health Information page at the Office of Dietary Supplements of the National Institutes of Health. The Office of Dietary Supplements, a part of the National Institutes of Health, works to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, stimulating and supporting research, disseminating research results, and educating the public about the efficacy and safety of dietary supplements to foster an enhanced quality of life and health for the U.S. population.

What are the different types of dietary supplements?

Dietary supplements fall into several distinct categories: (1) micronutrients - vitamins and minerals; (2) macronutrients - essential fatty acids (ALA and DHA), carbohydrates or saccharides, and amino acids; (3) phytochemicals, e.g., curcumin, lycopene, and isoflavones; (4) herbs (botanicals), e.g., St. John’s wort and Siberian ginseng; (5) zoochemicals, e.g., conjugated linoleic acid and bee pollen; and (6) miscellaneous types, e.g., probiotics, glucosamine, and melatonin. For more information, see the Fact Sheet for Consumers page at the Office of Dietary Supplements of the National Institutes of Health.

How big is the dietary supplement industry?

It is not easy to calculate the figure exactly, but the U.S. domestic dietary supplement industry is estimated to be a staggering $60 Billion in annual sales and is growing between 5 and 10% per year. For comparison, the production of animals for food was just under $3 Trillion in the U.S. in 2017. The worldwide sale of pharmaceuticals was just under $1 Trillion in 2013, and the U.S. accounts for more than a third of the global pharmaceutical market with $340 Billion in annual sales followed by the E.U. and Japan. Current revenue in the American cosmetics industry is roughly $60 Billion. Thus, while the dietary supplement industry is not as big as some of the others, it is huge and growing. About 80,000 dietary supplements are on the market today, and the Institute of Medicine estimates that 1,000 new products are introduced into the market every year.

Nutrition Business Journal. (2012). Nutrition Business Journal Supplement Business Report 2012. Cleveland, OH: Penton Media, Inc.

What are the leading condition-specific categories of dietary supplement sales?

The 10 leading categories of condition-specific dietary supplement sales are the following: (1) sports, energy, and weight control - $7.4 Billion; (2) general health - $4.5 Billion; (3) heart health - $2.0 Billion; (4) cold/flu and immune function - $2.0 Billion; (5) bone health - $1.8 Billion; (6) joint health - $1.6 Billion; (7) gastrointestinal health - $1.2 Billion; (8) diabetes/blood sugar control - $976 Million; (9) hair, skin, and nails - $556 Million; and (10) brain and mental health - $537 Million. The brain health niche is approaching the $2 Billion mark in sales globally. Up to this point, sales of brain health supplements have been driven by omega-3 fatty acids, the B vitamins, vitamin C, and phosphatidylserine. However, Dr Lewis Nutrition™ is creating product differentiation in the brain health niche with Daily Brain Care and its future products.


Nutrition Business Journal. (2012). Nutrition Business Journal Supplement Business Report 2012. Cleveland, OH: Penton Media, Inc.

Starling, S. (October 21, 2013). Global brain health market pushing $2bn mark as Asia and supplements shine. Accessed January 26, 2022.

How many Americans regularly take a dietary supplement?

According to the U.S. Centers for Disease Control and Prevention, among American adults at least 20 years of age and over, 58% used at least one dietary supplement in the past 30 days from the time the question was asked during the study, and more women (64%) had used a supplement than men (51%). Dietary supplements were more frequently used overall and in both sexes with advancing age, and the greatest overall use was among women 60 years of age and over (80%). Using two or more dietary supplements also increased with age. From 2007–2008 through 2017–2018, dietary supplement use increased among American adults of all ages. The typical dietary supplement user in the U.S. is an older, non-Hispanic white female who is physically active and has a higher level of education than average.


Centers for Disease Control and Prevention. (2003). National health and nutrition examination survey. Available at: Accessed January 26, 2022.

Freeman, J.W., & Landis, J. (1997). Alternative/complementary therapies. South Dakota Journal of Medicine, 50, 65-66.

Krastins, M., Ristinen, E., Cimino, J.A., & Mamtani, R. (1998). Use of alternative therapies by a low-income population. Acupuncture and Electrotherapeutics Research, 23, 135-142.

Mishra, S., Stierman, B., Gahche, J.J., & Potischman, N. (2021). Dietary supplement use among adults: United States, 2017–2018. NCHS Data Brief, no 399. Hyattsville, MD: National Center for Health Statistics. DOI:

Does the FDA regulate the sale of dietary supplements?

The U.S. Food and Drug Administration (FDA) does not approve dietary supplements for sale in the U.S., nor does the dietary supplement industry operate under product standardization with FDA oversight. Under the Dietary Supplement Health and Education Act (DSHEA) of 1994, a dietary supplement manufacturer must ensure that its products are safe before they are sold. Additionally, dietary supplement manufacturers are expected to operate according to Good Manufacturing Practices (GMPs), which are requirements related to manufacturing, preparation, and storage of products to ensure quality. Additionally, manufacturers have to guarantee the identity, purity, strength, and composition of their products. If a manufacturer is shown to violate any of these standards and/or cause harm to consumers, then FDA can take action to put the manufacturer out of business. Thus, FDA is responsible for acting against any unsafe dietary supplement product after it reaches the market. The U.S. Federal Trade Commission (FTC) oversees the advertising of dietary supplements in all media. The FTC mandates that all information about dietary supplements be honest and not deceptive. For more information, see the Frequently Asked Questions of the Health Information page at the Office of Dietary Supplements of the National Institutes of Health.

What is the Dietary Supplement Health and Education Act (DSHEA) of 1994?

The DSHEA was passed with the support of more than 70 Senate co-sponsors and more than half of the House of Representatives. Its major provisions were: (1) recognition of a new category of regulated food “Dietary Supplements” for the first time; (2) specification that the existing practice of regulating dietary supplements as food would continue including GMPs, claims, and no premarket approval requirement; and (3) prohibition by the FDA use of food additives process to regulate supplement ingredients. It created safety standards for dietary supplements, so that FDA: (1) can seize products that are adulterated or misbranded; (2) can remove a product from the market that presents a “significant or unreasonable risk of injury or illness;” (3) can remove from the market a dietary supplement that poses “an imminent hazard to public health or safety;” and (4) must be notified before a new dietary ingredient is introduced into the market. It created three categories of product and label claims: (1) Structure/Function claims that must be submitted to FDA with a required disclaimer; (2) Nutrient content claims; and (3) Health claims for the prevention or reduction of risk of disease with either (a) Full Unqualified Health claims that require significant scientific agreement, i.e., authoritative statement of scientific body or (b) Qualified Health claims with some scientific support, but not significant scientific agreement. Structure/Function claims are commonly used by dietary supplement companies for the following: (1) affect a structure or function in humans; (2) mechanism by which the compound or molecule acts to maintain such structure or function; (3) describe general well-being from consumption; (4) may not claim to diagnose, treat, cure, or prevent any disease; (5) require mandatory disclaimer and post-marketing notification; and (6) must have substantiation that statement is truthful and not misleading.

How do I determine if I need to take a dietary supplement and which one(s) should I take?

With so many choices, how do you decide what to buy? Purchasing a dietary supplement is similar to other consumer decisions, e.g., buying an automobile, with one big distinction: your decision could have a dramatic impact on your health. Thus, you should do your homework on the potential product (nutrient) and the company who manufacturers and/or sells it. One factor could be related to your current health status. If you are in good health, then you may think you do not need to take dietary supplements compared to someone currently faced with a health challenge. However, few people today are eating an optimally healthy diet, exercising as often as they should, and managing other health-related behaviors, as evidenced by the enormous epidemics of chronic diseases in the U.S., so everyone could benefit from taking dietary supplements. Another factor could be if you have a specific nutrient deficiency; some of the biggest ones being vitamins D and B12 and magnesium. Many Americans are not getting adequate levels of these micronutrients today, so dietary supplementation may be warranted in these cases. One of the biggest problems associated with the typical product on the market is the level of bioavailability or absorption of the active ingredient(s). If you are an athlete competing in a sport, according to the American College of Sports Medicine, adequate selection of nutrients and supplements, adjusting intake according to the exercise performed, is necessary for optimal performance. Additionally, does the product have supportive science that indicates it may be effective in having an effect on the intended organ (system) or your overall health? Here at Dr Lewis Nutrition™, we strive to bring you the most efficacious products backed by scientific scrutiny and evaluation, so that you not only have the best chance of being healthy, but you get the best value for your purchase.

What is bioavailability and why is it important?

Through the intake of food or supplements, we supply all nutrients to our bodies. Absorption takes place in the intestinal cells. These cells are covered with a fine water film. Only water-soluble substances that can permeate this water film are directly absorbed. The bioavailability and absorption of highly water-soluble substances, such as saccharides, salts, or vitamin C, are higher than fat-soluble substances. Fat-soluble substances cannot permeate the intestinal water film and have to be “pre-treated.” This pre-treatment takes place indirectly in the intestine by the formation of micelles using gall salts. These micelles allow fat-soluble nutrients and phytochemicals to be absorbed into the bloodstream. Otherwise, they would be excreted and the body would be unable to use them. Generally, the higher the level of bioavailability of a product or nutrient, the more of it your body’s end-target cells are ultimately able to utilize it for its physiological capabilities.


Heger, M., & Lewis, J.E. (2017). Dietary supplements and health: The essence of bioavailability. Available at: Accessed January 26, 2022.

What is cellular health?

The human body is comprised of trillions of cells. Each cell is pre-programmed to go through a cycle of life and death called apoptosis. This process is crucial for the body’s normal regeneration process, as all cells need to be replaced to ensure optimal functioning and health. Likewise, each cell is dependent on a sufficient supply of oxygen, elements, and other nutrients to function properly so that the normal apoptosis process occurs. As these raw materials are supplied to each cell, health is maintained, so that each cell can perform its functions properly.

Why is cellular health important?

Assuming a cell is healthy, it is able to conduct its functions properly. Some of these functions include oxidative respiration, phosphorylation, methylation, and enzymatic catalysis; all of which are essential for conducting the bioengineering of life. Cells become organs, which become organ systems. Our overall health is dependent on all cells functioning properly in harmony to allow us to live well daily. If cells, hence organs, are healthy, then ultimately the entire human system is healthy. Overall health requires all cells to be healthy and functioning properly.

What is the difference between healthspan and lifespan?

Life span is the total amount of time in a person’s life from birth to death, regardless of any measure of the quality of life in between. In comparison, healthspan is a recent term that is used to directly reflect the wellbeing of a person’s life in relationship to the number of years lived. Part of our philosophy at Dr Lewis Nutrition™ is that we endeavor to improve the healthspan by enhancing nutrition with the highest quality dietary supplements. As the scientific literature continues evolving, nutrition is most certainly now known as the number one behavior for achieving and maintaining health (or lack thereof with nutritional deficiency). Thus, besides eating an organic whole-food, plant-based diet, taking efficacious dietary supplements to augment the diet is your best strategy to ensure that you maximize your healthspan.

What is the definition of a clinical trial?

According to the U.S. National Institutes of Health (NIH), a clinical trial is: “A research study in which one or more human subjects are prospectively assigned to one or more interventions (which may include placebo or other control) to evaluate the effects of those interventions on health-related biomedical or behavioral outcomes.” Thus, a clinical trial is different from studies on cells and tissues (primarily in vitro or ex vivo), experiments on animals (pre-clinical), and epidemiological studies, where large groups of people are followed and measured over time with no regard for manipulating their behaviors or subjecting them to an intervention. Ideally, you want to look for dietary supplements that contain ingredients that are supported by clinical trials.

How are the results of research studies typically published?

Scientists can publish the results of their work in a few ways. The most credible way is to submit their findings in a written article to what is called a peer-reviewed journal. This form of periodical is different from a mainstream magazine that contains articles that are not scrutinized by one or more other scientists for legitimacy or accuracy. In the peer-review process, other scientists evaluate the findings for accuracy, suitability, worthiness, and other related factors deemed important to that particular journal. The process usually consists of one or more rounds of review, providing the authors the opportunity to respond to questions or edits suggested by the reviewers until the last version of the article is approved. At that point, the article is then put into the journal’s stream of upcoming articles to be included in a subsequent issue. This peer-review process ensures that scientists of equal or greater credentials and experience as the authors evaluate the work that has been done so that the article representing the body of work meets minimum requirements for the conduct of suitable science. This is the standard publication method through which all scientists must pass to share their work with others. Other methods of publication include presentations and lectures at conferences, workshops, and other meetings and summaries or abstracts of the full article in conference proceedings or symposia. These last two forms of publication may be peer-reviewed, but usually, they are not.

How can I understand the results of a research article about dietary supplements, nutrition, or health in general if I have no scientific training or experience?

Without an advanced university degree, e.g., Ph.D. or M.D., it may be difficult to fully understand a research article, particularly if the topic is very heavy in biochemistry, physiology, anatomy, or genetics. Even someone with an advanced degree may not fully understand the results of a study in a particular field that is outside his/her specialty or area of expertise. Thus, you may have to rely on interpreting as best as you can the summary of the study’s findings written in the abstract. The abstract is a condensed version of the full article that is meant to give you the gist of the findings as concisely as possible. Also, if you understand the concept of hypothesis testing, then you know that for most studies you are looking for a statistically significant difference, finding, or relationship at or below a certain level (usually p<0.05, i.e., 1 in 20 that some event occurred by chance). In addition to statistical significance, sometimes the concept of clinical significance is just as important. For example, a relationship might be statistically significant (p=0.02), but it has no clinical relevance because the finding does not translate into a useful distinction between treatments or groups of subjects. The converse could be true as well, i.e., a clinically significant finding that is not statistically significant, so you have to pay attention to the possibility of that situation as well. The bottom line is that it is difficult to fully understand or appreciate the findings of research for most people, but resources exist today online to help non-scientists understand science and you may be fortunate to have someone in your life who has a bit of training and experience who can help you wade through all of the jargon to discern what is relevant and meaningful for you.

    Newsletter Signup