The main COVID19 news item of the day is an Israeli study that just came out (in accepted manuscript form, i.e., after peer review) in FEBS Journal (FEBS=Federation of European Biochemical Societies).
The authors are affiliated with the medical schools of Tel-Aviv and Bar-Ilan Universities, as well as with the Leumit Health Services HMO (one of the four licensed HMOs in Israel — which has an HMO insurance mandate). They went through the Leumit patient database and looked at patients tested for COVID who had at least one recent blood test for vitamin D levels. Other health data were collected in order to correct for confounding factors. After screening, 782 COVID-19 positive and 7,025 COVID-19 negative patients remained. Note that the time window for COVID19 testing was February 1 to April 30, 2020 — i.e., before our sunny season.
From the abstract:
[…]“Suboptimal” or “low” plasma 25(OH)D level was defined as plasma 25-hydroxyvitamin D, or 25(OH)D, concentration below the level of 30 ng/mL.
Results: Of 7,807 individuals, 782 (10.1%) were COVID-19-positive, and 7,025 (89.9%) COVID-19-negative. […] Univariate analysis demonstrated an association between low plasma 25(OH)D level and increased likelihood of COVID-19 infection [crude odds ratio (OR) of 1.58 (95% CI 1.24-2.01, p<0.001)], and of hospitalization due to the SARS-CoV-2 virus [crude OR of 2.09 (95% CI 1.01- 4.30, p<0.05)]. In multivariate analyses that controlled for demographic variables, and psychiatric and somatic disorders, [these conclusions] were preserved. […]
Dr. John Campbell has been going hammer and tongs at vitamin D insufficiency on his YouTube channel, and an association has been shown by study after study. This is just the latest, and on a relatively large cohort.
I do know that dietitians in at least one HMO here have recently been told to routinely prescribe vitamin D supplements across the population. Presumably deficiency is less of an issue now in the summer than in winter.
At any rate: vitamin D deficiency is (for most people) cheap and easy to correct with supplements.
ADDENDUM: according to De Standaard (in Dutch) Belgium is seeing its highest new infection numbers in 3 months. A 3-year old toddler is among recent victims — underscoring that, while the risk of fatal complications is way lower in young people, it is not zero. The paper also reports on the aftermath of the disease in college-age young people: about 6,500 twenty-somethings got the disease in Belgium. Only few of those ever need to go to the hospital, but symptoms may linger for months afterward. The college students the paper interviews, months after surviving COVID19 bouts, still have symptoms such as fatigue, shortness of breath, chest pain,… A recent local medical survey found the following as most reported sequelae three months after infection: fatigue (86%), shortness of breath (53%), headache (41%), muscle pain (40%) and a sensation of pressure on the chest (36%).