Letter: Vitamin D deficiency in rheumatoid arthritis.
D000983:Antipyrine / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000150:complications*; D006801:Humans; D011803:Quinine / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications*
D011803:Quinine; D000983:Antipyrine