The supermarket and drugstore shelves are filled with different brands of multivitamins. How do you know which ones, if any, will truly make a difference to your health? Do you go by price or by celebrity endorsement? I hope the following points help you to make an informed choice.

1. Bioavailability

This is one to the top factors that determine the effectiveness of your multivitamin! Bioavailability is defined as the degree and rate at which a substance is absorbed into a living system or is made available at the site of physiological activity. What good does it do to take a supplement if it is not effective due either to low amounts of nutrients or poor bioavailability? It seems obvious that all vitamins should have high bioavailability but it isn’t the case. How can you tell? While all dietary supplements manufactured or sold in the USA must meet FDA regulations and must comply with established Good Manufacturing Practices (GMPs), these do not specify minimal standards for bioavailability. However, some manufacturers voluntarily comply with the United States Pharmacopeia (USP) standards and specifications for potency, uniformity, and disintegration which are the same standards used for pharmaceutical drugs. This information should be on the container (see example). Additionally, some supplement manufacturers obtain third-party verification of their GMP practices. These may include NSF International ( and the NSF logo will be on the package or on the supplement manufacturers’ website.

check that it is independently lab tested
2. Completeness

The body requires a wide spectrum of vitamins, minerals, and other nutrients to work together. In fact, Nutrisearch (, an independent nutritional research organization, has identified 47 nutrients which should be included in a ‘gold standard’ multivitamin.

3. Potency

All multivitamins must list the quantity of the nutrient contained in each tablet/capsule and the corresponding percentage of the recommended daily intake (DI). However, many of the DI’s are based on the minimum amounts required to prevent disease, not to optimize health. When considering the nutritional needs for prevention of disease and optimal health, many nutritional experts consider the current DI for many nutrients to be too low.

4. Mineral Forms

Minerals are essential critical structural components of the body, are used to regulate the actions of nerves and muscles, and modulate the pH of cells and extracellular fluids.  But the molecular form of the minerals is important.  To increase the bioavailability  of minerals (how well they are absorbed by the body), many manufacturers chemically bond the mineral to an amino acid or organic acid carrier. These chelated minerals are believed to mimic the natural mineral chelates that form during digestion. They are easier to absorb and are better tolerated by the gut than the mineral salts found in less expensive multivitamins.

5. Vitamin E forms

Vitamin E is a potent antioxidant that protects cells and tissues from oxidative damage induced by free radicals. Its activity is wide-ranging. Because it is a fat-soluble vitamin, its protective effects involve the inhibition of fat oxidation in the gut, blood stream, tissues, and cells. These actions result in protection against several important degenerative disorders, including Alzheimer's disease, certain cancers, and - most notably - heart disease. Sound clinical evidence supports the value of vitamin E supplementation. However, as with the mineral forms discussed above, the form in which it’s used is important. The natural form of Vitamin E, d-alpha tocopherol, is considered much more effective than the synthetic form (d/l-alpha tocopherol) and the additional use of gamma tocopherol is thought to reduce inflammation and protect against colon and prostate cancer.

6. Immune Support

Both Vitamin D and iodine have been the focus of research over the past decade and are considered vital components to our immune systems. Other nutrients, such as vitamins A, C, E, zinc, selenium, the B vitamins (B1, B2, B5, B6, and B12) and folic acid should also be included as they contribute to a healthy immune system.

7. Bone Health

In order to promote healthy bones, the following nutrients should be included in the multivitamin: calcium, magnesium (increases calcium retention in the bones), phosphorus (must be in balance with the amount of calcium), vitamins D and K (also aid in calcium deposition), manganese, silicon, boron, zinc and copper (all help to strengthen the bone’s mineral matrix), vitamin C (aids in calcium crystallization), vitamins B6, B12, and folic acid (reduce mineral loss).

8. Heart Health

Intake of the following nutrients is related to reduced risk of cardiovascular disease: antioxidants vitamin E and beta-carotene, vitamin D and iodine, coenzyme Q10, calcium and magnesium.

9. Metabolic Health or Glucose Control

Diabetes is a chronic disorder of carbohydrate, fat, and protein metabolism and is well on its way to reaching epidemic-like levels in the western world. It is characterized by high insulin and blood-sugar levels. Dietary and lifestyle changes may help, including supplementation with several vitamins and minerals essential for metabolic support and regulation of glucose metabolism. These include: vitamins B3, B6, B12, C, E, D, iodine, coenzyme Q10, chromium, magnesium, manganese, and zinc.

10. Potential Toxicities

In some cases, high levels of certain vitamins and minerals are not a good thing. For example, vitamin A (retinol form) is fat-soluble and can be toxic when high levels are taken over an extended time. Pregnant women should also reduce the amount of vitamin A consumed because of an increased risk of birth defects. The upper limit is recognized to be 3 mg (or 10,000 IU)/day, although individual tolerances may vary. Excessive iron consumption can cause deterioration of the gut lining, vomiting and diarrhea, abdominal and joint pain, and intense fatigue. High doses of iron may also be implicated in a higher risk for cardiovascular disease. Because of the seriousness of the potential toxicity, iron should not be part of a multivitamin.

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    • Thanks for the comment. The more important issue is how much time it takes to dissolve in the stomach. The USP standards state that it must disintegrate within 30 min.

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    About the Author Sharon Walt

    Dr Sharon is a certified Functional Medicine Health Coach who helps men and women with autoimmune disorders, such as Hashimoto's Thyroiditis, regain their health and start living life to the utmost again.