Vitamin D and calcium are among the most popular supplement ingredients in the U.S., but recent tests by ConsumerLab.com, White Plains, NY, showed problems with four out of 25 products that contain these ingredients. Pills of two popular brands of supplements failed to properly break apart, suggesting their ingredients may not be fully available for use by the body. One of these products also contained too much vitamin D (172.5% of the listed amount) as did a widely-sold, candy-like supplement, which contained 182.2% of its listed amount of vitamin D. Lead contamination was found in a fourth product.

In a survey of more than 10,000 supplement users by ConsumerLab.com this past November, 55.5% of respondents reported using a vitamin D supplement daily, making vitamin D the third most popular supplement after fish oils/omega 3 supplements and multivitamins. Calcium was the fifth most popular supplement, coming after CoQ10, and was used by 48.4% of respondents.

In a separate report, ConsumerLab.com highlighted the difficulty consumers have in selecting a supplement containing the antioxidant CoQ10 or its activated form, ubiquinol. ConsumerLab.com’s recent tests found that one popular supplement provides only 3.8% of its listed amount of CoQ10. Even among products found to contain their listed ingredients, consumers should choose carefully, the company cautioned. ConsumerLab.com found the cost of a 100 mg dose of CoQ10 to range from 9 cents to several dollars. Some products include additional ingredients, such as those that may improve absorption of CoQ10 and ubiquinol, but may not necessarily justify a higher cost.