Research shows low vitamin D levels almost certainly promote COVID-19 infections, hospitalizations, and deaths.
Over 100 scientists and doctors now published an open letter and call for immediate widespread increased vitamin D intakes.
In this dramatic appeal, the doctors highlight the benefits of supplementing vitamin D3 in the battle against COVID-19:
Vitamin D modulates thousands of genes and many aspects of immune function, both innate and adaptive. The scientific evidence hows that:
- Higher vitamin D blood levels are associated with lower rates of SARS-CoV-2 infection.
- Higher D levels are associated with lower risk of a severe case (hospitalization, ICU, or death).
- Intervention studies (including RCTs) indicate that vitamin D can be a very effective treatment.
- Many papers reveal several biological mechanisms by which vitamin D influences COVID-19.
- Causal inference modelling, Hill’s criteria, the intervention studies & the biological mechanisms indicate that vitamin D’s influence on COVID-19 is very likely causal, not just correlation.
Furthermore they assert they call on all governments, doctors, and healthcare workers worldwide to immediately recommend and implement efforts appropriate to their adult populations to increase vitamin D, at least until the end of the pandemic.
- Recommend amounts from all sources sufficient to achieve 25(OH)D serum levels over 30ng/ml (75nmol/L), a widely endorsed minimum with evidence of reduced COVID-19 risk.
- Recommend to adults vitamin D intake of 4000 IU (100mcg) daily (or at least 2000 IU) in the absence of testing. 4000 IU is widely regarded as safe.
- Recommend that adults at increased risk of deficiency due to excess weight, dark skin, or living in care homes may need higher intakes (eg, 2x). Testing can help to avoid levels too low or high.
- Recommend that adults not already receiving the above amounts get 10,000 IU (250mcg) daily for 2-3 weeks (or until achieving 30ng/ml if testing), followed by the daily amount above. This practice is widely regarded as safe. The body can synthesize more than this from sunlight under the right conditions (e.g., a summer day at the beach). Also, the NAM (US) and EFSA (Europe) both label this a “No Observed Adverse Effect Level” even as a daily maintenance intake.
- Measure 25(OH)D levels of all hospitalized COVID-19 patients & treat w/ calcifediol or D3, to at least remedy insufficiency <30ng/ml (75nmol/L), possibly with a protocol along the lines of Castillo et al ‘20 or Rastogi et al ’20, until evidence supports a better protocol.
Many factors are known to predispose individuals to higher risk from exposure to SARS-CoV-2, such as age, being male, comorbidities, etc., but inadequate vitamin D is by far the most easily and quickly modifiable risk factor with abundant evidence to support a large effect. Vitamin D is inexpensive and has negligible risk compared to the considerable risk of COVID-19.