The 4 parathyroid glands are located near or attached to the back side of the thyroid gland and produce parathyroid hormone (PTH). Parathyroid hormone regulates calcium, phosphorus, and magnesium balance within the blood and bone by maintaining a balance between the mineral levels in the blood and the bone.
Review Date 5/2/2016
Updated by: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.