Parathyroid hormone (PTH) is involved primarily in mineral homeostasis, especially that of calcium. PTH is lowered when there is sufficient vitamin D, dietary calcium, and magnesium, while it is promoted by serotonin. PTH can impair mitochondrial metabolism, and promote systemic inflammation and other stress systems. Hyperparathyroidism can also promote digestive issues like constipation, heartburn, nausea and loss of appetite.