Vitamin D can be taken for many reasons, including the treatment of osteoporosis and osteogenesis imperfecta, which is a condition where the bones are brittle and susceptible to breakage. However, people with these conditions might not be getting the treatment they need if they’re taking over-the-counter supplements.
A new study conducted at Kaiser Permanente Center for Health Research indicates that vitamin D supplement labels may be woefully misleading. Specifically, you may be receiving far more or far less vitamin D in each pill or tablet than the label would lead you to believe. Pills tested in the study contained as little as 9% and as much as 146% of the vitamin D indicated on the labeling. These inaccuracies and inconsistencies could pose serious danger to individuals who are taking supplements to rectify low vitamin D levels, according to lead researcher Dr. Erin LeBlanc.
Most Supplements are Labeled Inaccurately
During the study conducted in Portland, Oregon, researchers measured actual vitamin levels in 12 different vitamin D supplements, all from different makers. The supplement bottles were purchased from five separate stores, and the researchers analyzed five pills from every bottle. According to the supplements’ labeling, the pills were supposed to contain anywhere from 1,000 to 10,000 IUs (International Units) of vitamin D.
Only one-quarter of the supplements contained between 90% and 120% of their indicated vitamin D dosage across all five pills. This is considered a safe and normal margin of error in terms of supplement manufacturing processes. Further, the average of the five pills was similar to the indicated dosage for these three bottles.
Look for the USP Mark
One of the bottles tested during the study had received certification from the U.S. Pharmacopeial Convention, or USP. When a manufacturer creates a new supplement, they can send their product to USP for testing and certification. In order to receive USP certification, the supplement must be tested to provide from 90% to 120% of what’s listed on the bottle. The particular bottle of USP-certified supplements was very accurately labeled, according to the findings of the study. Dr. LeBlanc says that although very few supplements have USP certification, the ones that do are worth seeking out.
Cause for Concern?
According to Dr Pieter Cohen, assistant medicine professor at Harvard Medical School, inaccurate labeling on supplements, including ones that deliver vitamin D, should be alarming to the medical community. He said that many of his patients take vitamin D supplements, and is concerned that inaccurate labeling could leave them confused as to whether they’re actually meeting their daily requirements.
Cohen believes that inaccurate labeling is a problem exclusive to supplements, and not over-the-counter and prescription medications that are actually regulated by the Food and Drug Administration (FDA).
Under today’s laws, the FDA can penalize manufacturers of supplements if vitamin and mineral levels in their products don’t accurately match the labeling. Cohen sees the Kaiser Permanente study as evidence that these laws aren’t being enforced properly. Unfortunately, the FDA does not inspect supplements before they’re brought to market.
The Bottom Line
If you take a vitamin D supplement, check the labeling to ensure that the product has received certification from USP. If it hasn’t, it’s very possible that the supplement contains a far different vitamin D dosage from what the label indicates, according to a new study.
The full text of the study can be found online in JAMA Internal Medicine.