Please note: This article has been updated with the release of the NutriSearch Comparative Guide to Nutritional Supplements, 5th Consumer edition.

There are, in fact, two things, science and opinion;
The former begets knowledge, the latter ignorance.

Product Rating Criteria

This chapter explains the Health Support Profile, a set of mathematical models based on the 18 Health Support criteria described below. The Health Support Profile provides an overall ranking for each product included in this guide in accordance with the nutrient intake recommendations as described in the Blended Standard. Together, the Blended Standard and the 18 Health Support criteria form the basis of our analysis. For a detailed explanation of the Blended Standard, please refer to the previous chapter.

To evaluate a product, its rating for each Health Support criterion is calculated mathematically. This rating is determined by the nutrients and their potencies present in the product in relation to the requirements for each criterion. Next, these 18 individual ratings for each product are pooled to provide a raw product score for that product. These scores, separated statistically into percentile ranks, represent a product's rating relative to all products evaluated. Final product ratings are displayed as star ratings, shown in half-star increments from zero to five stars.

The five-star scale is, at once, both visual and intuitive: a five-star rating represents a product of the highest quality relative to all products evaluated in accordance with the comprehensive NutriSearch Health Support Profile used in our analysis. Conversely, a one-star rating or less represents products possessing few, if any, of the characteristics for optimal nutrition as reflected in the Blended Standard.

This Health Support Profile is described in detail below. For a more detailed explanation of each criterion and the science supporting its development, the reader is referred to the NutriSearch Comparative Guide to Nutritional Supplements,™ 5th (Professional) Edition. Our website also includes the complete description of each criterion, along with the relevant scientific references. Please visit us online at

The NutriSearch Health Support Profile

To receive a full point for any single Health Support criterion, the product must meet or exceed the benchmark established for that criterion. Each criterion uses a sliding scale, from 0% to 100%, where partial points are awarded for the partial fulfillment of the criterion. The last criterion, Potential Toxicities, penalizes the product if the formulation exceeds defined limits of daily intake for those nutrients (vitamin A and iron) that demonstrate potential cumulative toxicities.

The following discussion provides an overview of each criterion used in our Health Support Profile. For each criterion, we address the fundamental question posed; in turn, each question presents the logical argument that forms the basis of our mathematical model for that criterion.

1. Completeness

The human body requires several vitamins and vitamin-like substances, a diverse group of plant-based antioxidants, numerous trace elements and minerals, and several essential fatty acids. Many of these substances can only be obtained through the diet. In all, 47 essential nutrients and nutrient categories comprise our Blended Standard—the definitive benchmark upon which our analysis is built. This criterion assesses whether the product contains all of the Blended Standard nutrients.

2. Potency

The potencies for the 47 essential nutrients and nutrient categories used in our Blended Standard reflect the need for supplementation with some nutrients at levels considerably higher than their Dietary Reference Intakes (DRIs). This criterion assesses how much of each nutrient the product contains compared to the Blended Standard.

3. Mineral Forms

Minerals are essential components of our cells and serve as cofactors in the thousands of enzyme-controlled reactions that power the machinery of the cell. Throughout the body, minerals also form critical structural components, regulate the action of nerves and muscles, maintain the cell's osmotic (water) balance, and modulate the pH (acidity) of the cell and extracellular fluids. While minerals comprise only 4% to 5% of our total body weight, life would not be possible without them. This criterion examines mineral forms (mineral salts, chelated minerals, or organic-acid/mineral complexes), which affect the ability of the minerals to be absorbed into the blood, making them available to our cells.

4. Vitamin E Forms

Vitamin E comes in many different forms, each of which has important benefits in cellular function. In its natural form, the most common type of vitamin E is d-alpha tocopherol; synthetic vitamin E (commonly found in supplements as d/l-alpha tocopherol) is only half as effective as the natural form. Another form of vitamin E, gamma tocopherol, possesses distinctive chemical properties that differentiate it from alpha tocopherol. Studies show that gamma tocopherol reduces chronic inflammation and protects against cancers of the colon and prostate better than its alpha analogue. This criterion assesses the product for the various forms of vitamin E and their bioactivity.

5. Immune Support

An explosion of research over the past decade has uncovered vitamin D as a vital component to our immune systems. Working in conjunction with other micronutrients, vitamin D can help protect us against many of the most common degenerative diseases, including heart disease, stroke, cancer, multiple sclerosis, dementia, and many others. Unfortunately, this new research coincides with a dramatic downturn in vitamin D intake amongst North Americans. Many other nutrients, particularly other vitamins, are also essential to a healthy immune system. This criterion assesses the product for vitamin D levels and the presence of other nutrients that boost immune response.

Another nutrient recently discovered as vital to immune support is iodine. The high iodine concentration of the thymus gland is prima facia evidence of the important role played by iodine in the immune system—a role likely related to the element's innate antioxidant powers.1-3

Many other nutrients, including vitamin A, vitamin C, vitamin E, zinc, selenium, and the B-vitamins B1, B2, B5 (pantothenic acid), B6, B12 and folic acid, are also essential to a healthy immune system.4 This criterion assesses the product for vitamin D and iodine levels and for the presence of these other nutrients that boost the immune response.

6. Antioxidant Support

The weight of scientific evidence supports supplementation with antioxidants in the prevention and treatment of many of today's common ailments. As was anticipated decades ago by leading researchers,5 high-dose supplementation with antioxidants has gained a significant role in the prevention and treatment of many of today's common ailments. However, antioxidants do not work in isolation. For this reason, it is vital to supplement with a wide spectrum of antioxidants—an approach that is reflective of what occurs in nature. This criterion examines the nutrients that help to prevent or repair cellular damage caused by oxidation.

7. Bone Health

As living tissue, healthy bones require at least 24 bone-building materials, including several vitamins, minerals, trace elements, and protein. The most ­important minerals are calcium, magnesium, phosphorus, and potassium; equally important is the balance between these minerals. This criterion examines the nutrients in a product that assist in bone remodeling, a process vital in warding off osteoporosis and other diseases that weaken the skeletal framework.

8. Heart Health

Individuals with high dietary intakes of antioxidant vitamins, certain minerals, and several plant-based flavonoid compounds exhibit a lower-than-average risk of cardiovascular disease. This criterion examines several nutrients, including the recently discovered cardioprotective powerhouses—iodine and vitamin D—that are known to benefit the heart and cardiovascular system by reducing oxidative stress and suppressing inflammation.

9. Liver Health (detoxification)

Intracellular glutathione status is a sensitive indicator of cellular health and of the cell's ability to resist toxic challenges. An important water-phase antioxidant, glutathione is one of three vital free radical scavenging mechanisms in the cell. It is also the body's pre-eminent detoxicant in the liver. While dietary glutathione is efficiently absorbed in the gut, the same is not the case for nutritional supplementation.

Iodine is another important nutrient for liver health and detoxification. Iodine's ability to staunch the potential damage of hydrogen peroxide provides support for the work of the glutathione peroxidase enzyme system in helping to remove these toxic agents from the body. This criterion examines those nutrients that optimize levels of glutathione and enhance liver function.

10. Metabolic Health (glucose control)

Diabetes is a chronic disorder of carbohydrate, fat, and protein metabolism. The disease begins as a constellation of metabolic changes associated with chronically high insulin levels and elevated blood-sugar levels, a condition known as Insulin Resistance. The development of insulin resistance is multi-factorial; however, complications associated with this pre-diabetic disorder can be resolved effectively through conscientious dietary and lifestyle changes, including supplementation with several vitamins and minerals essential for metabolic support and the close regulation of glucose metabolism. This criterion examines those nutrients that help the body handle its daily sugar load, keeping systems responsive to insulin and restoring lost insulin sensitivity.

11. Ocular Health

Good eyesight and the prevention of cataracts and macular degeneration require adequate levels of several nutrients known to reduce the level of oxidative stress in the retina and lens of the eye.

12. Methylation Support

Over 40 major clinical studies confirm that high homocysteine levels are a predictive marker for heart disease, stroke, and peripheral artery disease. In fact, up to 40% of patients with heart disease express elevated levels of homocysteine. Deficiencies in certain B-complex vitamins are known to increase circulating levels of homocysteine; conversely, supplementation with these nutrients can significantly reduce circulating homocysteine by converting it to harmless methionine and cysteine. This criterion looks at those nutrients required for the body to reduce homocysteine levels in the blood

13. Lipotropic Factors

The liver and the brain are two primary targets for the accumulation of fat-soluble toxins, including pesticides and heavy metals (such as lead). Within the liver, choline and inositol assist with the elimination and removal of these noxious compounds through their ability to mobilize fats and bile. Known as lipotropic (fat-moving) factors, these agents have a long history of use within the naturopathic community, helping to restore and enhance liver function and treat a number of common liver ailments. This criterion examines those lipotropic agents that help the liver mobilize fats stores and remove toxins.

14. Inflammation Control

Chronic inflammation, frequently induced by uncontrolled oxidative stress, is a principal mechanism by which degenerative disease takes root. Changing the balance within the body to favour the production of anti-inflammatory chemical messengers and lower the levels of inflammation is therefore an important preventive measure. This criterion examines the nutrients responsible for reducing inflammation at the cellular level, such as the omega-3 oils—particularly those found in fish oil (eicosapentaenoic and docosahexaenoic acids, or EPA and DHA) and alpha-linolenic acid (flaxseed and other oils).

Recent evidence shows that Vitamin D also expresses potent anti-inflammatory actions. The hormone activates several genes controlling the manufacture of an inflammation-suppressing chemical, Interleukin-10 (IL-10), produced in specialized white blood cells. IL-10, in turn, dampens the body's over-response that can often precipitate allergic reactions. As well, iodine—likely in its molecular form—exhibits anti-inflammatory and anti-proliferative activities that are important factors in determining cardiovascular health,6-9 and in reducing the risk of inflammatory cancers of the breast, stomach, endometrium, and ovaries.10; 11

15. Glycation Control

Aging—the outcome of the conflict between chemistry and biology in living systems—introduces chronic, cumulative chemical modifications that compromise the structure and function of important biomolecules within our cells. We now know that changes to these molecular structures, driven by unrelenting oxidative stress, can render them dysfunctional. Their accumulation, the detritus of an ongoing oxidative war within the cell, is a hallmark of the aging process. This criterion examines those nutrients that help slow the progress of glycation.

16. Bioflavonoid Profile

The flavonoids are known as "nature's biological response modifiers" because of their ability to alter the body's reactions to allergens, viruses and carcinogens, and to protect cellular tissues against oxidative attack. Flavonoids, found in the edible pulp of many fruits and vegetables, impart a bitter taste when isolated. Citrus fruits, such as oranges, lemons, limes, grapefruit, and kiwi, are particularly rich sources of flavonoids. This criterion examines the bioflavonoid family of nutrients, which works throughout the body to attack free radicals, suppress inflammation, and support a myriad of bodily functions.

17. Phenolic Compounds Profile

The weight of scientific evidence supporting the health benefits of polyphenols is immense. They are powerful free radical antagonists, recognized for their ability to reduce cardiovascular disease and cancer, and they demonstrate potent anti-inflammatory, anti-viral, anti-bacterial, anti-allergic, anti-hemorrhagic, and immuno-enhancing properties. The most intensely studied of the phenolic compounds include those isolated from: turmeric, a perennial herb of the ginger family and a major ingredient in curry; green tea, a rich source of compounds called catechins; and extracts from the fruit of the olive tree. This criterion examines these specific phenolic compounds, all of them known to be exceptionally potent free radical antagonists.

18. Potential Toxicities

In order to optimize its preventive benefits, the strategy of nutritional supplementation is to encourage long-term use. Consequently, there exists a potential risk for consumers with regard to the cumulative toxicity of particular nutrients. Most nutrients used in nutritional supplements have a high degree of safety; however, some nutrients require a degree of prudence when it comes to long-term use. Both iron and vitamin A (retinol) can become toxic when taken in high doses over a long period. Accidental overdose of iron-containing supplements is, in fact, a leading cause of fatal poisoning in children, and too much vitamin A during pregnancy can cause birth defects. Vitamin A is available, safely, as beta carotene, while adequate iron is easily obtained, for most people, from a variety of foods. This criterion examines the levels of pre-formed vitamin A (retinol) and iron in the product and penalizes the product rating if it contains too much of either nutrient.


The 18 individual Health Support ratings, as described above, are pooled for each product to provide a raw product score. These scores are then separated statistically into a percentile rank, which represents a product's rating relative to all products evaluated. Final product ratings are displayed as star ratings, shown in half-star increments from zero to five stars. The five-star scale is, at once, both visual and intuitive: a five-star product represents a product of the highest quality relative to all products evaluated in accordance with the comprehensive NutriSearch Health Support Profile used in our analysis. Conversely, a one-star rating or less represents products possessing few, if any, of the characteristics for optimal nutrition as reflected in the Blended Standard.


  1. Kupper FC, Carpenter LJ, McFiggans GB et al. Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry. Proc Natl Acad Sci U S A 2008;105:6954-6958.
  2. Patrick L. Iodine: deficiency and therapeutic considerations. Altern Med Rev 2008;13:116-127.
  3. Venturi S, Venturi M. Iodine in evolution of salivary glands and in oral health. Nutr Health 2009;20:119-134.
  4. Murray MT and Pizzorno J. Immune Support. Encyclopedia of Natural Medicine. Prima Health, Rocklin CA; 1998;145-160.
  5. Crary EJ, McCarty MF. Potential clinical applications for high-dose nutritional antioxidants. Med Hypotheses 1984;13:77-98.
  6. Cacace MG, Landau EM, Ramsden JJ. The Hofmeister series: salt and solvent effects on interfacial phenomena. Q Rev Biophys 1997;30:241-277.
  7. Hatefi Y, Hanstein WG. Solubilization of particulate proteins and nonelectrolytes by chaotropic agents. Proc Natl Acad Sci U S A 1969;62:1129-1136.
  8. Hoption Cann SA, van Netten JP, van NC. Iodized salt and hypertension. Arch Intern Med 2002;162:104-105.
  9. Hoption Cann SA. Hypothesis: dietary iodine intake in the etiology of cardiovascular disease. J Am Coll Nutr 2006;25:1-11.
  10. Clur A. Di-iodothyronine as part of the oestradiol and catechol oestrogen receptor--the role of iodine, thyroid hormones and melatonin in the aetiology of breast cancer. Med Hypotheses 1988;27:303-311.
  11. Thomas BS, Bulbrook RD, Goodman MJ et al. Thyroid function and the incidence of breast cancer in Hawaiian, British and Japanese women. Int J Cancer 1986;38:325-329.

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About Us

NutriSearch Corporation is a Canadian company specializing in nutrition and health research, focussed primarily on multiple vitamin and mineral supplementation.

Our main product is the NutriSearch Comparative Guide to Nutritional Supplements , which examines current research on the health benefits of supplementation for prevention of degenerative disease. The guide also includes comparisons of broad-spectrum supplements available in various markets around the world, including Canada and the US (in our Professional Edition), North and South America (our new Guide for the Americas), and a combined edition for Australia and New Zealand. The Professional Edition is larger and includes additional scientific information; it is intended for health professionals and consumers looking to learn more about nutrition and health. Our Americas and ANZ guides are more consumer-friendly but contain most of the same content and, of course, product comparisons for their respective regions.

NutriSearch is also available as a consultant to nutritional supplement manufacturers wanting to improve their supplements.