Does Your Vitamin C Supplement Deliver as Promised?

Vitamin C is an essential water-soluble vitamin that provides a myriad of benefits. It helps the body produce collagen, aids iron absorption, acts as an antioxidant, may protect the body and boost the immune system when under stress and may help maintain the effectiveness of nitrate drugs such as nitroglycerin.

The human body cannot manufacture vitamin C; therefore it must come from foods or supplements. The richest food sources include vegetables such as broccoli and brussel sprouts, as well as citrus and other fruits.

Vitamin C is the top selling single vitamin in the United States. According to Nutrition Business Journal, vitamin C had sales of $863 million in 2006.Vitamin C supplements are typically sold as ascorbic acid, Ester C or calcium ascorbate, sodium ascorbate, or a combination of these forms. They also commonly contain natural sources of vitamin C such as rose hips and/or acerola.

The U.S. Food and Drug Administration (FDA) requires that any vitamin C sold as a dietary supplement in the United States contain at least 100 percent of its labeled amount. However, the FDA doesn’t test for quality before sales. Fortunately, there are independent agencies that evaluate health, wellness and nutrition products and provide results and information to consumers to enable them to make informed choices.

It is one of the leading independent test results providers, ConsumerLab.com (CL), who recently completed their fourth review of vitamin C supplements. They tested 23 brands for nutrient content; 16 were chosen by ConsumerLab and the other seven tested at the request of the manufacturer. They also tested the tablet and caplet products for their ability to disintegrate properly for absorption.

The report included these brands in alphabetical order: Advocare, Child Life, Douglas Laboratories, Dynamic Health Laboratories, Emergen-C, GNC, Halls, Longs, Member’s Mark (Sam’s Club), Nature Made, Nature’s Bounty, Nature Smart , New Chapter, NF Formulas, Nutrition Now, Origin (Target), Puritan’s Pride, Rainbow Light, Schiff, Swanson, Trader Darwin (Trader Joe’s), Vitamin Shoppe, and Vitamin World.

The results? Twenty-two of the products met their claims for vitamin C and all tablets disintegrated properly for absorption. However, one product, Dynamic Health Laboratories Liquid Vitamin C contained only 43.5 percent of its claimed amount of nutrient, yielding only 435 mg of vitamin C per tablespoon when claiming 1,000 mg in its “Supplement Facts” labeling. ConsumerLab says the missing vitamin C could be due to the fact that liquid supplements are more susceptible to degradation than non-liquid forms, and say they have found the same problems in liquid products they have tested in the past.

ConsumerLab also found two products whose suggested doses exceeded Upper Tolerable Intake Levels (UL):

• Advocare C-grams High Potency Vitamin C 500 mg caplets, with dosing instructions of up to four per day would provide 2,000 mg, exceeding UL of vitamin C for those under the age of 19.
• Emergen-C 1,000 mg Vitamin C as a seven mineral Ascorbate 32 Mineral Complexes B Vitamins Cranberry Flavored Fizzy Drink Mix with directions for two to four per day would give a total of 2,000-4,000 mg, exceeding UL of vitamin C for not only those under age 19 but for all age groups.

ConsumerLab says that their initial review of vitamin C in 2001 revealed several products containing fewer nutrients than claimed and one product would not disintegrate properly but recent years have been generally positive.

Make sure your brand of vitamin C supplement has passed the test. If not, you might consider finding one that has a proven reputation.