Vitamin D is relevant to proper functioning of immune system, however it seems that it is hard to find "the right amount" for everyone as it depends on several factors.
I'm wondering if Vitamin D intake can improve response against recurring infections like flu, sometimes they can bring you down several times in a season, so it takes quite a heavy toll on productivity and mood.
https://www.ncbi.nlm.nih.gov/m/pubmed/28768407/
Vitamin D is relevant to proper functioning of immune system, however it seems that it is hard to find "the right amount" for everyone as it depends on several factors.
I'm wondering if Vitamin D intake can improve response against recurring infections like flu, sometimes they can bring you down several times in a season, so it takes quite a heavy toll on productivity and mood.