Increased serum sulfate after protein loading in adult humans

To determine the effects of a protein loading on sulfate metabolism in humans, we monitored serum sulfate concentrations in 12 fasting adult volunteers fed a high-protein meal of egg white and an isocaloric low-protein meal. With each subject serving as his or her own control, we found that mean serum sulfate rose only slightly with the low-protein meal but was significantly higher with high-protein loading at 3 and 3.5 h. The median of the peak sulfate concentration was 57% greater than baseline with the high-protein meal versus 11% with no loading. Since changes in serum sulfate have been shown to influence the rate of sulfation for a variety of different acceptor molecules, these observations indicate a means by which protein feeding may simultaneously influence diverse metabolic pathways.