People continue to want to argue whether the scientific evidence that low vitamin D raises COVID-19 risk exceeds their preferred standard for scientific certainty, but this question is backwards when set in the context of widespread D deficiency/insufficiency. (1/7)

Most governments set serum D level minimum targets of 20ng/ml (50nmol/L) & many professional societies (eg Endocrine Society) suggest 30ng/ml as the min target. 33-50% of people worldwide (& in many individual countries including US) fall below 20ng/ml. More below 30ng/ml. (2/7)

Certain groups (care home residents, dark skinned, those with obesity, etc.) have higher rates of deficiency. D intakes should rise to fix these unhealthy levels, by widespread world scientific consensus. That's up to 2019. Now COVID-19 comes along. And slowly new data.... (3/7)

Now much varied evidence (hundreds of papers, dozens now peer reviewed & published) strongly suggests that lower D levels increase risk and/or that D is an effective treatment. Many people think current evidence to date is conclusive enough. Many don’t. Arguments fly. (4/7)

But zero evidence suggests the opposite: that it’s better for COVID-19 to have low D or a good idea to induce deficiency as a treatment. And there is zero controversy about this. There is also essentially zero risk in moving from <30ng/ml levels to 30-40 or even 50ng/ml. (5/7)

To continue to argue whether the evidence conclusively proves D is helpful for COVID-19 to someone's chosen bar for scientific certainty is the wrong question, and I would argue in fact actively harmful. Even the flipped is-low-D-helpful question would be better framing. (6/7)

The right question is what does current data tell us about which serum range for D likely minimizes total risk (COVID19 + others). Answer: current data overwhelmingly points to >30ng/ml as better than <30. Much better than <20. The world should act on this data immediately. (7/7)