text: <unk>  is a vitamin deficiency disease caused by dietary lack of niacin (vitamin B3) and protein, especially proteins containing the essential amino acid tryptophan. Because tryptophan can be converted into niacin, foods with tryptophan but without niacin, such as milk, prevent<unk> . However, if dietary tryptophan is diverted into protein production, niacin deficiency may still result.
  Tryptophan is an essential amino acid found in meat, poultry, fish, and eggs. If your diet contains these foods, your need for niacin from other sources will be reduced.
  The relationship between lysine and<unk>  is unclear.
option_0: Pellagra
option_1: Koilonychia
option_2: Melanonychia
option_3: Leukonychia
option_4: Xanthelasma
option_5: Platonychia
option_6: Blepharophimosis
option_7: Melasma