A balanced diet that provides all essential nutrients is important for everyone. Otherwise, only a few specific dietary recommendations are justified for types of porphyria other than the acute Porphyrias.
ALAD porphyria (Porphyria due to a deficiency of 8-aminolevulinic acid dehydratase). Effects of diet on this extremely rare condition have not been reported. However, because it bears some resemblance to the acute porphyrias, at least some of the same nutritional considerations may apply.
Congenital Erythropoeitic Porphyria. Diet does not appear to play a specific role in this rare condition. The excess porphyrins in this rare condition originate from the bone marrow. The heme biosynthetic pathway in the bone marrow seems to be much less sensitive than in the liver to changes in carbohydrate and energy intakes. Because patients with this condition may be severely ill, however, their diets may be inadequate. Such nutritional deficiencies should be prevented because they may contribute to anemia and other manifestations.
Porphyria Cutanea Tarda. Even though porphyrins in this condition originate from the liver, carbohydrate and energy intakes have not been described as major determinants of disease activity. However, excess iron and alcohol are clearly important. Alcohol and iron supplements should be avoided. Restriction of dietary iron is usually not necessary.
Erythropoietic Protoporphyria. Excess protoporphyrin in this condition originates primarily from the bone marrow, which as noted above is not highly sensitive to changes in energy and carbohydrate intakes. The bone marrow is sensitive to iron deficiency which, therefore, should be prevented by assuring an adequate intake of iron. Iron supplements should probably not be given unless laboratory tests for iron suggest that stores of this mineral are low.
Occasionally, the liver seems to contribute significantly to excess protoporphyrin production in Erythropoietic Protoporphyria and there can be significant liver damage. For this reason, patients with this condition may be advised to follow dietary recommendations similar to those for patients with the acute forms of Porphyria.