et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2020-000151 (Peer Reviewed)
Analysis of vitamin D levels and COVID-19 cases and severity based on genetic predisposition to higher vitamin D levels or lower vitamin D deficiency, finding no significant association.
For some background on Mendelian randomization studies and their limitations see .
Amin et al., 1/7/2021, retrospective, United Kingdom, Europe, peer-reviewed, 2 authors.
COVID-19 severity, 32.3% higher, RR 1.32, p = 0.20, odds ratio converted to relative risk, >=50nmol/L vs. <25nmol/L, MR Egger, baseline risk approximated with overall risk.
risk of COVID-19 case, 7.6% higher, RR 1.08, p = 0.14, odds ratio converted to relative risk, >=50nmol/L vs. <25nmol/L, MR Egger, baseline risk approximated with overall risk.
Effect extraction follows pre-specified rules prioritizing more serious
outcomes. For an individual study the most serious outcome may have a smaller
number of events and lower statistical signficance, however this provides the
strongest evidence for the most serious outcomes when combining the results of