The present invention relates to pharmaceutical composition for effective utilization of calcium comprising of elemental calcium, along with essential co-factors viz. elemental magnesium, zinc and vitamin D supplemented with vitamin C useful for administration to the subjects in need thereof, especially for increasing bone growth, or for bone matrix formation or increasing the bone mineral density or treating bone loss in osteoporotic patients, or post-menopausal women and/or elderly men treating age-related bone loss or in pregnant or lactating women and the process for the preparation of the same in stabilized oral dosage forms.