Does Intravenous Iron Therapy Decrease Serum Phosphorous Levels?

Intravenous iron therapy is common and effective, with few side effects. Two formulations are used, venofer or iron sucrose and ferrlecit, or ferric gluconate. The association between intravenous iron use and decrease in serum phosphorus and vitamin D levels, with increased fractional excretion of phosphorus, has been observed with older iron preparations, such as saccharated ferric oxide. However, hypophosphatemia and osteomalacia have been reported with iron carboxymaltose, a newer iron formulation. There is no information in the literature about phosphorus and vitamin D levels after treatment with venofer or ferrlecit. We intend to check phosphorus and vitamin D serum levels in our patients prior to and after treatment with these iron formulations.