Dr. Zorba Paster: Vitamin D plays important role in keeping us healthy, perhaps with COVID-19, too

Vitamin D – should you take it? Should everyone take it? Should it be seasonal – take it in the winter, don’t take it in the summer? Does it prevent COVID-19? Does it cure COVID-19?

Lots of D buzz. There has been lots of interest in the vitamin for years and years.

Let’s talk rickets, the hallmark of vitamin D deficiency in children. When the Industrial Revolution hit, child labor hit. Kids didn’t get vitamin D. In cities like Boston, nearly 80% of kids had mild or severe cases of rickets, which causes weak and soft bones, stunted growth and in severe cases skeletal deformities. When this essential vitamin, which allows your body to absorb calcium, was added to milk in the 1930s, it wiped out rickets.

The D is added when milk is homogenized, as it is a fat-soluble vitamin – the goal being to evenly distribute the D in the milk. Every quart of milk contains 400 IU to 600 IU of D, which is equivalent of stripping down naked and standing in the sun at noon for 15 to 20 minutes. Just try that next January and see how you feel. You can see how D supplementation changed the world.

By the way, you can get Vitamin D naturally from fatty fish like salmon, herring, tuna or swordfish – but who can get a kid to eat that daily? Or you can go back to that old standard, cod liver oil, 1 teaspoon daily. (But, it tastes awful!)

The NIH recommends 600 IU every day for adults. But many researchers recommend you really need 2,000 IU daily. And yet others think daily vitamin D might prevent COVID-19 or, if you have COVID-19, help you recover. So where is the data? And is there a downside? That’s always what I think about when it comes to supplements.

Several years ago, there was a large study, the beta carotene CARET study, which showed that taking beta carotene supplementation when you were a smoker increased, not decreased, your risk factor for lung cancer. We know that eating carotene-rich foods are good for you and might, might is the word, help prevent cancers.

But somehow supplementation did harm, just the opposite. That’s when I realized the “no harm, no foul” idea behind supplements should be revisited – they might not be beneficial or harmless at the least; they might be harmful.

Some research points to low D being associated with diabetes mellitus, cardiovascular disease, depression, autoimmunity and even pregnancy complications. Low prenatal and early life vitamin D levels might also increase susceptibility to schizophrenia and multiple sclerosis. In later life, in the elderly, higher risk of vitamin D deficiency and lower vitamin D status have been reported to be associated with increased fall risk.

All this is speculative – none of it proven, but that’s because it’s not easy to do massive, double-blind, placebo-controlled studies to prove or disprove it. Now there is abundant proof that low vitamin D levels is associated with tuberculosis and respiratory infections, although supplementation with D doesn’t seem to help in treatment.

So what about COVID-19? There is abundant evidence that people of color, including African Americans, Pacific Islanders and Native Americans, are three to four times more likely to die from COVID-19 than Caucasians. There are lots of confounding factors for many, not all, in this population – financial, social, accesses to medical care, health literacy, etc. Some believe that vitamin D might be a major player not only in preventing COVID-19 infection, but also in its treatment.

One prospective study of 50 hospitalized patients treated with calcifediol, equal to a 4,000 IU daily dose of the usual supplement, showed that only one required admission to the ICU (2%), while of 26 untreated patients, 13 required admission (50%). The low levels of vitamin D in untreated patients are responsible, in part, for the increased death rate.

My spin: Lots of people are vitamin D deficient, roughly half of the U.S. population. The older you are, especially if you are chronically ill, the more likely you are to have low D. I don’t think there is a downside for vitamin D supplementation – and the upside might be important, especially during this influenza and COVID-19 season.

How much to take? Some data show that a Caucasian younger than 50 who is completely healthy can get by with 2,000 IU daily. But for everyone else, or anyone who has concurrent medical conditions, take the 5,000 IU. If you just want to take the higher dose, do it – no harm, no foul.

If you have COVID-19, up it to 10,000 IU until you’re completely better. You can get a one-year supply of this for $20. Cheaper than your health insurance copay.

Dr. Zorba Paster is a family physician and host of the public radio program “Zorba Paster on Your Health.” He can be reached at askzorba@doctorzorba.com.