what kind of vitamin or mineral will relax your muscles
Calcium and Magnesium. Calcium and magnesium work together to control muscle contraction. Both minerals interact with the proteins actin and myosin -- structural proteins that shorten with each muscle contraction, then lengthen to relax your muscles. Actin and myosin rely on calcium to shorten and contract your muscles, then rely on magnesium to relax after a contraction. While low calcium levels primarily affect your bones -- causing bone loss and putting you at risk for osteoporosis -- magnesium deficiency affects your muscles, causing abnormal muscle contraction.
A common deficiency found in older people, Vitamin D can help discomfort and aching in the muscles. Vitamin D also helps in the absorption and utilization of calcium in the blood, which is required to soften and relax the muscles when they begin to cramp or tighten. The main source for vitamin D is from direct sunlight.