Zahler's Magnesium Citrate is a naturally occurring mineral that helps maintain many functions in the body, most notably the muscles and nerves. Magnesium also increases water in the intestines, thereby aiding in relieving occasional constipation. More about Magnesium: Zahler’s Magnesium Citrate is a bioactive high potency magnesium supplement. Magnesium is needed for more than 300 metabolic reactions in the body. It helps maintain normal muscle and nerve function, keeps the heart rhythm steady and keeps the bones strong. This highly absorbable, fast-acting magnesium supplement helps regulate both blood sugar and blood pressure levels, alleviates constipation, contributes to energy production and helps normalize the levels of many important nutrients.