Adults in India consume on an average about half the amount of calcium than required for healthy bones, according to a global map of dietary calcium intake launched on Friday. Calcium is a major component of bone, accounting for between 30-35 per cent of its mass and much of its strength. Low calcium intake has been linked to lower bone-mineral density, which increases the risk of osteoporosis and broken bones. In India, the average calcium intake is only 429 mg per day against the requirement of 800-1000 mg per day, according to the map launched by the International Osteoporosis Foundation (IOF), a nongovernmental organisation.