We know that vitamin D is important for bone health, but apart from that, the research observations may have been embellished. It appears that healthy lifestyle changes like weight loss, diet, and exercise can also naturally increase blood levels of vitamin D. I believe, as do other experts, that healthy people are making vitamin D look good and it is not the vitamin D supplements that are necessarily making people more healthy.
In other words, when body inflammation increases, the blood level of vitamin D starts to decrease for many. So, it could be that vitamin D doesn't prevent or treat many diseases but is a marker of disease activity.
It's for this reason that many recent clinical trials and meta-analyses have failed to show a benefit from use of vitamin D supplements. For example, a two-year randomized trial of vitamin D to reduce osteoarthritis did not work, and a recent review of vitamin D supplements to reduce blood pressure concluded vitamin D has minimal to no impact.
Critics would argue that the doses of vitamin D have not been large enough in these and other clinical trials, but this is not exactly accurate. In fact, there are plenty of studies to suggest that taking megadoses of vitamin D or raising blood levels of vitamin D too much can increase the risk of short- and long-term toxicity.
More: Your Vitamin D Cheat Sheet
Do You Need a Vitamin D Supplement?
A ConsumerLab.com report also suggested that more is not better in terms of the blood level of D. It only takes 1,000 International Units (IU) of vitamin D—the amount in most multivitamins—to raise your blood test 10 points. In fact, it's likely you already get enough vitamin D from the sun, food, and beverages without any additional supplementation.
ConsumerLab.com recommends asking your doctor for a vitamin D test if you think you're low, but this might not make make "cents" for everyone. A periodic test may provide some value, but if your insurance doesn't cover the vitamin D blood test, one test could cost you hundreds of dollars. For this reason, I don't advise many patients to get a regular vitamin D test unless they are dealing with serious bone health issues (like osteoporosis or bone fracture). Not to mention, the vitamin D blood test has not been adequately standardized, which means researchers do not know the accuracy and reliability of it.
ConsumerLab.com also recommended getting more sunshine if your blood level is below 20 nanograms per milliliter (ng/ml), but I think that this is just trading one disease for another. Ultraviolet light from the sun is obviously a carcinogen, and aggressive skin cancer in younger individuals is dramatically on the increase while age-adjusted rates of most cancers are on the decline. If your levels are this low, I would rather you consume more foods with vitamin D or take a low-cost supplement compared to getting more sun.
Also, if you do require supplementation to get your levels up, take the vitamin with whatever meal contains the most fats and oils. Research shows that taking vitamin D with food increases absorption (though to varying degrees). Plus, there are always fewer side effects when taken with food.
More: Raise Your Vitamin D Without Pills
Clean, Cheap Supplements
Most of the vitamin D supplements ConsumerLab.com reviewed passed the group's quality-control testing, and that's great news. In fact, of the 42 total vitamin D products tested, an impressive 39 passed. (I wish herbal products had this kind of track record—I like to dream big!)
Interestingly, the three products that did not pass contained slightly less or more of the vitamin than what had been reported on the label and were pretty pricy. These products are:
• Country Life Bone Solid—While this supplement had the claimed amount of vitamin D, it only had only 127 micrograms (mcg) of vitamin K though it claimed 166 mcg.
• Shaklee OsteoMatrix—This supplement was found to have 490 IU more vitamin D than indicated on the label (1,096 IU rather than the 600 IU claimed on the package).
• Hero Nutritionals Yummi Bears: This children's product contained only 89 IU of vitamin D, when its label claimed it contained 100 IU.
More: 7 Doctor-Approved Ways to Avoid Bogus Supplements
If you look at the products that passed testing, some of the cheapest products had the best quality control, which means they contained exactly the amount of vitamin D reported, did not exceed the contamination limit for lead, arsenic, and cadmium, and they "disintegrated properly," meaning they were easy to digest.
Some notably clean and inexpensive supplements include:
• GNC Vitamin D-3, 1,000 IU per tablet costs only 6 cents per day.
• Simply Right by Sam's Club vitamin D, 2,000 IU per softgel is 2 cents per pill.
• If you want to use vitamin D drops, then Source Naturals vitamin D-3 costs only a penny a day for 400 IU of vitamin D.
• Swanson High-Potency Vitamin D3, 1,000 IU costs only 2 cents per day.
• Carlson Super Daily D3 Baby, 400 IU for children is only 3 cents a day.