Supporting your point, the ACX post on COVID and Vitamin D cites this study finding that Vitamin D levels are relatively stable.
Relevant from the abstract: “The 25(OH)D levels were correlated between visits 2 and 3 (3 y interval) among whites (r = 0.73) and blacks (r = 0.66).”
Supporting your point, the ACX post on COVID and Vitamin D cites this study finding that Vitamin D levels are relatively stable.
Relevant from the abstract: “The 25(OH)D levels were correlated between visits 2 and 3 (3 y interval) among whites (r = 0.73) and blacks (r = 0.66).”