Calcium builds and maintains strong bones and teeth. Your body also needs it for muscle contraction, nerve signaling, and blood clotting.
Calcium supplements fill dietary gaps when food intake falls short. People take them to help maintain bone density, especially with age, and to keep muscles and nerves working normally.
Take calcium with a meal to absorb it better. Stomach acid from food helps break down calcium carbonate, the most common supplement form. Splitting the daily dose into a morning and evening half can boost total absorption.
Side effects can include constipation or gas. High-dose calcium supplements, especially calcium carbonate, can raise the risk of kidney stones. Some research has linked high-dose calcium to cardiovascular problems.