This 2018 review explores the immunomodulatory roles of vitamins A and D in allergic diseases. Animal studies indicate that deficiencies in these vitamins exacerbate allergic symptoms and lung inflammation, while supplementation, particularly with vitamin D, can attenuate these effects. Active metabolites—retinoic acid (RA) from vitamin A and 1,25-dihydroxyvitamin D3 (VD3)
