Fish oil, multivitamins, vitamin D, calcium and CoQ10 are the most popular supplements among those who take them, according to a survey of more than 10,000 consumers of supplements. More than two-thirds of respondents used fish oil and/or multivitamins, while approximately half used vitamin D, calcium, and/or CoQ10. Results are based on responses from ConsumerLab.com’s (White Plains, NY) survey of its e-newsletter readers conducted in November 2011.

The survey showed women are much more likely than men to take vitamin D, calcium, B vitamins, probiotics and iron supplements. Men are more likely than women to take supplements that are generally thought to boost energy, slow aging, or lower cholesterol, including CoQ10, resveratrol, amino acids, red yeast rice, nutrition drinks and powders, green tea, vitamin K, plant sterols and muscle enhancers. Men are also more likely than women to take supplements for sexual enhancement.

Many supplements are especially popular with older consumers. For example, while only 31% of respondents under 35 use vitamin D, use of the vitamin increases to just more than 50% for those ages 45 to 54 and to 58% for those ages 65 to 74. Other supplements that are especially sought after by older consumers include calcium, CoQ10, B vitamins, vitamin C, vitamin E, resveratrol and vitamin K. Conversely, the use of some supplements declined with age, including amino acids, nutrition/protein drinks and powders, green tea, nutrition bars, weight loss supplements, muscle enhancers and super fruits. Younger adults are also slightly more likely than older adults to have recently used fish oil or multivitamins.

Not surprisingly, the most heavily used supplements are especially popular among people who take multiple supplements every day. This is particularly true with fish oil, used by 81% of people who took 10+ supplements per day. CoQ10 is used by 76% of people who take 10+ supplements per day but only by 10% of people using one supplement per day.

In addition to the consumer survey, Consumer.Lab.com issued a report covering more than two dozen probiotics. Tests found that the actual number of living organisms in probiotics don’t always match the claims on the label. “Probiotics can be helpful, but you need to choose products carefully,” said Tod Cooperman, MD, president of ConsumerLab.com. “Not every product has what it claims and even those that do may not have the right type and amount of organisms for your condition.”

Probiotics represent one of the largest and fastest growing segments of the dietary supplement market, with sales up 19% to $636 million in 2010, according to Nutrition Business Journal, Boulder, CO. A survey of more than 10,000 supplement users by ConsumerLab.com in November 2011 found probiotics were used by 34% of women and nearly 28% of men. Probiotics are also one of the most expensive dietary supplements, with a daily dose averaging $1.06.

Of 12 probiotic products for adults and children selected for testing by ConsumerLab.com, two delivered far fewer organisms than promised. One contained just 57% of the organisms listed on the label and the other had 65%. Still, all products provided at least 1 billion organisms per day, an amount that may provide some benefit. Products were also tested for microbial contaminants and pathogens, but none were found. Tests also showed that products sold as caplets and enteric-coated capsules were able to properly release their ingredients.

ConsumerLab.com also found variance among zinc supplements in a separate analysis after purchasing popular zinc supplements, testing their contents and reviewing their dosage against products shown to work in clinical studies.

Zinc lozenges have been shown to reduce the duration and symptoms of a cold if taken properly. However, among four marketed zinc lozenges, only one provided the proven dosage. A specific formula of zinc with antioxidants is known to reduce the progression of advanced macular degeneration, as demonstrated in the large Age-Related Eye Disease Study (AREDS). ConsumerLab.com found that two of the purchased products met this specification. Although nearly identical, one product cost 30% less than the other.

Zinc supplementation may be useful in treating other conditions including acne, depression and anorexia nervosa, as well as to prevent and correct zinc deficiency. ConsumerLab.com found that most general-use zinc supplements met quality standards. Although lead contamination can occur in zinc supplements, none of those tested were contaminated. However, a large variation in price was found, with the cost to obtain 50 mg of zinc ranging from as little as 3 cents to as much as 18 cents, or even more for products with additional ingredients.