Serum ionized magnesium and calcium and sex hormones in healthy young men: importance of serum progesterone level

Objective: To determine the serum concentrations of the sex hormones with respect to the concentrations of the biologically active fractions of magnesium (Mg) and calcium (Ca) in healthy young men and to compare them with those in young and older women. Design: Controlled clinical study. Setting: An academic research environment. Patient(s): Twenty-five healthy young male volunteers. Intervention(s): None. Main Outcome Measure(s): Concentrations of the sex steroid hormones testosterone, estrogen, and progesterone, and levels of ionized Ca (Ca2+) and Mg (Mg2+) were measured in the serum of healthy young men. These levels were compared with those in young women at different phases of the menstrual cycle and with those in older women. Result(s): The Mg2+ and total Mg concentrations in young men were not different from those during the follicular phase in young women or from the mean concentrations in menopausal women. The Ca2+ levels in young men were similar to the levels in young women during the follicular phase but significantly lower than the levels in older women. The Mg2+ concentration in the young men was directly and significantly related to the progesterone level, and the Ca2+/Mg2+ ratio was inversely related to the progesterone level. Conclusion(s): Progesterone may be a more important steroid hormone in men than previously believed. (Fertil Steril(R) 1999;72:817-22. (C) 1999 by American Society for Reproductive Medicine.)