Decreased plasma phosphate under hormonal contraceptives.
Plasma phosphate (Pi) and several indices of Ca-Pi metabolism were measured in 129 randomly selected healthy female individuals of the general population, of whom 59 were on hormonal contraceptives and 70 were not. Fasting plasma Pi was significant (p less than 0.01) lower in those taking hormonal contraceptives (0.96 +/- 0.17 mmol/l) than in those not taking them (1.06 +/- 0.16). Those on hormonal contraceptives had identical age, body weight and UVcr. Systolic and diastolic blood pressure was higher in those on hormonal contraceptives, and there was an inverse relationship between blood pressure and plasma Pi. Between those on hormonal contraceptives and those not on them, no significant difference of urinary cAMP (non-hormone 4.69 +/- 1.48 nmol/l GF; hormone 4.43 +/- 1.18) or iPTH could be shown. The present study documents that hormonal contraceptives with estrogen (less than or equal to microgram/dl) decrease plasma Pi and urinary Ca in premenopausal nonosteoporotic women.