Lack of vitamin C: lack of upper respiratory illness.
D001205:Ascorbic Acid / Q000494:pharmacology / Q000627:therapeutic use*; D001206:Ascorbic Acid Deficiency / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012141:Respiratory Tract Infections / Q000209:etiology*; D012614:Scurvy / Q000150:complications
D001205:Ascorbic Acid