Most people do not think much about the quality of their vitamin supplements. They just assume that the FDA is protecting them from sub-par manufacturing. Sorry to disappoint. The FDA can barely keep up with prescription drugs, let alone dietary supplements. When it comes to the quality of your vitamin D you are pretty much on your own, as this reader points out:
Q. You responded recently to a man who was trying to get his vitamin D levels up after being treated for prostate cancer. You should have mentioned something about taking a high quality supplement.
Not all supplements are equal. When my vitamin D level was tested a year ago, it was very low even though I took vitamin D pills daily. My naturopath put me on a high-quality D (changing nothing else) and within six months my level was where it needed to be. People must be educated about the vital importance of quality in their supplements.
A. Your point is valid. A study in JAMA Internal Medicine (April 8, 2013) found extreme variability in dose among vitamin D supplements. Some pills had as little as 9 percent of the dose on the label while others had up to 140 percent.
ConsumlerLab.com Test Results:
The FDA does not monitor the quality of dietary supplements, so consumers are on their own. ConsumerLab.com tests supplements, but you will have to pay for the reports.
We can mention that ConsumerLab.com found quite a few D supplements that met their standards. We have personally used Nature Made and Life Extension with seemingly good results but we make no endorsements of any vitamin D products. By the way, if you look at the vitamin D review in ConsumerLab.com you will find a number of Q&As that that are useful and you won’t have to subscribe (or pay) to benefit from the answers.
Does Time of Day Matter?
A prostate oncologist told us that when he has patients who cannot get their vitamin D levels into the recommended zone he often encourages them to take their vitamin right after dinner. His experience was that this enhanced absorption and was more effective than taking D after breakfast.
The good news about vitamin D is that you can monitor your progress. Discuss with your doctor what the target range should be and then periodically have your blood tested to see if you have reached that goal.
And don’t forget that a few minutes (10 to 15 in the summer) can often provide good vitamin D levels the natural way. Most dermatologists will not get too aggravated with such short exposure times, as long as you don’t burn your skin.
Does Vitamin D Make A Difference for Prostate Cancer?
We are still awaiting really well-controlled clinical trials to demonstrate the benefits of vitamin D in either preventing recurrences or improving mortality stats. Nevertheless, there are data to suggest that there is a sweet spot for D (Dermato-endocrinology, May 16, 2016). Too much or too little is where people get into trouble.
To learn more about the pros and cons of vitamin D, the sweet spot and how to interpret laboratory values we offer our Guide to Vitamin D Deficiency at this link.
