Topic summary
Immune function
Extracted from the Wikipedia article Immune system.
Vitamin D
Although early cellular studies suggested vitamin D might influence immune responses, more recent large-scale clinical trials and meta-analyses (2022–2024) have found that vitamin D supplementation can reduce the risk and severity of autoimmune diseases such as rheumatoid arthritis and multiple sclerosis, and may modestly reduce the incidence of acute respiratory tract infections and improve tuberculosis outcomes. A 2011 United States Institute of Medicine report stated that "outcomes related to ... immune functioning and autoimmune disorders, and infections ... could not be linked reliably with calcium or vitamin D intake and were often conflicting."