Spray might be effective for COVID

Dear Dr. Roach: Am I taking too many vitamins, and are there benefits in taking all these vitamins? I started taking fish oil for my heart; 2,000 IU of vitamin D3 was suggested by my gastroenterologist; a multi-vitamin because my mom has macular degeneration; and I started taking zinc and vitamin C because I heard it will help with COVID symptoms. K.P.A.

Answer: Vitamins in reasonable doses are seldom dangerous, although some can be at very high doses.

Fish oil has been shown to modestly improve blood pressure and cholesterol, and a prescription version reduced heart attack risk in people with high triglyceride levels in one study. In another study in people taking statins, fish oil had no benefit.

Vitamin D has been very controversial. Recent studies have found that vitamin D did not “prevent cancer or cardiovascular disease, prevent falls, improve cognitive function, reduce atrial fibrillation, reduce migraine frequency, decrease age-related macular degeneration or reduce knee pain.” Of course, there are some people who still benefit from vitamin D, such as people with osteoporosis, who cannot absorb vitamin D well, or who live where they never get sun. The 2,000 IU you are taking is safe.

People with the dry form of macular degeneration benefit from a particular multivitamin (called the AREDS or AREDS 2 formulation) to slow progression of this condition that affects central vision. However, studies designed to show prevention of macular degeneration with the same formulation could not show a benefit. Again, though, there is no harm from these supplements, except that smokers should not take the original AREDS formulation, since they had a higher risk of lung cancer.

Multiple studies have looked to see whether vitamin C, zinc or vitamin D can prevent COVID-19 or reduce its severity; unfortunately, the preponderance of the evidence shows no convincing benefit. Taking supplements is no substitute for vaccination and prudent behavior. Scientists have not proven that vitamin and mineral supplements benefit you for the conditions you are concerned about, but it is still possible that there is a benefit that is too small to find within the types of studies already done. The downside of these particular supplements at reasonable doses is small.