What the Evidence Actually Shows on Vitamin D, Vitamin E, CoQ10, and Beta-Carotene

Full analysis

Dr. Philip Snider walked through the evidence on four commonly taken supplements. Vitamin D: bone health is well established, and correcting a deficiency (a blood level below 30) is supported by evidence. It has not been shown to reduce all-cause mortality overall, though there is a small, not-yet-confirmed signal suggesting it may reduce cancer mortality. Some clinicians push levels to 40–50 for chronic pain, which is well below toxic range. Vitamin E: research hoped it would reduce inflammation and help with liver disease, but high doses increase bleeding risk, especially when combined with aspirin, ginkgo, or ginseng — raising the risk of hemorrhagic stroke. CoQ10 (coenzyme Q10): has some evidence for people with heart failure, and anecdotal support for reducing muscle aches caused by statin medications (the cholesterol-lowering drugs many older adults take). Dr. Snider said CoQ10 does not appear to interact with newer blood thinners such as Eliquis, but older warfarin (also called Coumadin) users should be cautious with all supplements because warfarin interactions are numerous. Beta-carotene: a large trial in the 1990s showed that high doses actually increased lung cancer risk in smokers — a clear example of a supplement causing harm rather than benefit.