What to Look For in a Dietary Supplement?

Not all dietary supplements are alike. Supplements can offer forms that are poorly absorbed, contain harmful excipients or have inferior quality standards so it is important to choose wisely. While the FDA has increased its oversight in the past few years, it is still important to choose supplements that meet the highest quality standards. New manufacturing regulations require companies to follow cGMP’s (current Good Manufacturing Practices), focusing on minimum quality standards to ensure that supplements do not contain contaminants and are accurately labeled. Unfortunately, it is often up to the company to determine the scope of these minimum quality standards.

Choosing a company with high quality standards is the first step in finding the best dietary supplements. It is important to look for established reputable companies that will make the proper investments to provide quality. Companies that are not well established do not have the same reputation to uphold. Additionally, you should look for a company that does extensive independent third party testing. High-quality established independent labs are more likely to provide unbiased results compared with in-house testing. Minimum quality standards could be as basic as in-house identity testing, or could be as extensive as third party testing for potency, solvents, pesticides and heavy metals. It is important to ask the company what the quality standards entail.

The nutrients themselves are another important element of a quality dietary supplement. Certain forms of nutrients have relatively low bioavailability ( i.e. oxides) or can alter the pH of the digestive tract (i.e. carbonates) and therefore may be less well absorbed. Companies often choose these inorganic forms because they are smaller molecules and it is easier to fit higher levels per serving, however they are not as well absorbed as organic (carbon-containing) chelates (i.e. citrate, glycinate or picolinate). The best forms of minerals are fully chelated and bound to amino acids or Kreb's cycle intermediates. Chelation is the binding of the elemental mineral (for example, calcium) to another molecule. A fully chelated mineral means that none of the mineral is left unbound. The body is primed to recognize amine acids and kreb's cycle intermediated (examples include picolinates, aspartates, citrates, malates and glycinates) and therefore these compounds are better absorbed.

Additionally, vitamins should be in both the traditional highly researched forms and in active forms. Active forms are those that are found in body and do not need to be converted in order to be utilized. For example, folic acid is a synthetic, oxidized form of folate that requires enzymatic reduction in order to function as a methyl donor. The efficiency of this conversion is dependent on an individual's genetic profile. A certain percentage of the population lacks the ability to efficiently make this conversion. Therefore, folate should be provided as 5-MTF 5-methyltetrahydrofolate) rather than folic acid. Similarly, methylcobalamin, pyridoxal-5-phosphate and riboflavin-5-phosphate are in forms that are utilized by the body and would not need to be converted.

Lastly, look for a dietary supplement that contain few excipients. Excipients are additional ingredients used as binders, fillers, lubricants, preservatives, colors and flavors that are added to dietary supplements. These ingredients can impair absorption and often have limited research on the health impact of long-term use.

Some examples of common excipients include:

• Magnesium stearate, a common lubricant, is suggested to suppress immune function
• Methylparabens may cause hormone disruptions. Parabens have been found in high concentrations in breast cancer tumors
• Food colors and artificial flavors have been linked to hyper-activity and irritability in children

Last but not least, when choosing a multivitamin it is important to look for one that contains at least 100% of the dietary reference intake (DRI) values (DRI is a replacement for the older RDA values. The percent daily value (%DV) on labels is based on the old RDA levels). It is also important to avoid exceeding the upper limit (UL) for any nutrients. The upper limit is the maximum amount of a vitamin or mineral which is unlikely to cause harm. My recommended range is determined by the amount that has been typically studied in the literature and generally falls somewhere between the RDA/DRI values and upper limit levels.

Multivitamin/Mineral Recommendations

Nutrient	DRI	UL	Recommended Range	Notes
Vitamin A and/or beta-carotene	2300-3000 iu (700-900 mcg)	10,000 iu (3,000 mcg)	3,000-10,000 iu	Look for a combination of preformed vitamin A and beta-carotene
Vitamin B1 (thiamine)	1.1-1.2 mg	ND (not determined)	>1.1 mg
Vitamin B2 (riboflavin)	1.1-1.3 mg	ND	> 1.1 mg	Look for riboflavin 5'-phosphate in addition or in place of standard riboflavin
Vitamin B3 (niacin)	14-16 mg	35 mg	14-35 mg (higher levels of niacinamide ok)	Look for niacinamide or combinations of niacin and niacinamide. High doses of niacin can cause flushing, while niacinamide does not cause flushing and has been associated with pancreatic health
Vitamin B5 (pantothenic acid)	5 mg	ND	> 5 mg
Vitamin B6 (pyridoxine)	1.3 mg	100 mg	1.3-100 mg	Look for pyridoxal 5'-phosphate in addition or in place of standard riboflavin
Vitamin B12	2.4 mcg	ND	250-1,000 mcg	Look for methylcobalamin, the activated form used by the body. Vitamin B12 needs increase with aging as stomach acid (and therefore absorption) decreases
Folate	400 mcg	1,000 mcg	400-1,000 mcg	Look for 5-methyltetrahydrofolate (5-MTHF) the activated form used by the body
Biotin	30 mcg	ND	> 30 mcg
Choline	425-550 mg	3,500 mg	>100 mg	Choline is often missing from multivitamins but is an important nutrient for cognitive function
Vitamin C (ascorbic acid)	75-90 mg	2,000 mg	75-2,000 mg
Vitamin D	400 iu (10 mcg)	4,000 iu (100 mcg)	1,000-4,000 iu	Look for vitamin D3, which is more easily utilized than vitamin D2
Vitamin E	15 iu	1,000 iu	15-400 iu	Look fort a vitamin E containing mixed tocopherols or gamma tocopherol as well as alpha-tocopherol
Vitamin K	90-120 mcg	ND	> 90 mcg	Look for vitamin K2 (menaquinone-7) which can help maintain calcium balance in the vascular tissues
Calcium	1000-1200 mg	2,500 mg	100-500 mg per svg (1-3 times per day)	Based on balance studies recommendations may be between 700-1,200 mg, however the body is unable to absorb more than 500 mg of calcium at a time (including the calcium from foods)
Magnesium	320-420 mg	400 mg	100-400 mg	Levels of magnesium glycinate can exceed 400 mg without a laxative effect, however higher levels of other forms of magnesium can have a laxative effect
Iron	10-15 mg	45 mg	0-45 mg	Generally, iron should only be supplemented in individuals at risk for iron deficiency
Zinc	12-15 mg	40 mg	15-40 mg
Iodine	150 mcg	1,100 mcg	150-1,100 mcg
Selenium	55-70 mcg	400 mcg	55-400 mcg	Look for selenomethione
Copper	0.9 mg	10 mg	0.9-2 mg
Chromium	25-35 mcg	ND	25-600 mcg
Manganese	1.8-2.3 mg	11 mg	1.8-10 mg
Molybdenum	76-109 mcg	2,000 mcg	76-2,000 mcg
Aresenic, Boron, Nickel, Silicon, Vanadium	ND	ND