Iron metabolism in porphyria cutanea tarda.

The iron metabolism has been studied in 11 patients with porphyria cutanea tarda. Despite significantly increased amounts of iron in the serum and liver, the porphyria patients absorb not less but significantly more radioiron than normal controls. Whereas phlebotomy-induced iron deficiency stimulates the absorption in controls, no further stimulation is found in the porphyria patients. The plasma iron turnover is high in the porphyria patients, and some of this iron is probably deposited in the liver. The relationship between the high iron absorption, high plasma iron turnover, high liver iron, liver damage and uroporphyrin production in the liver is discussed. It is suggested that two concurrent genetic defects may cause porphyria cutanea tarda, one in iron absorption and one in porphyrin synthesis by damaged liver cells. The absorption of inorganic iron was higher than that of hemaglobin iron. The possible damage which fortification with inorganic iron could cause to the very small group of porphyria patients is discussed.