Currently, there is no commonly practiced tool for assessing calcium status of individuals or populations. Few biochemical markers reflect calcium status. Fasting urinary calcium:creatinine ratios may hold promise as an easy, inexpensive method to indicate recent calcium status. Calcium status may best be assessed by integrated measures of calcium assimilation, such as total-body calcium. Although bone-mass measurements do not correlate well with recent dietary intakes of calcium, long-term adequacy of calcium intake influences bone mass. Whether low calcium intakes lead to calcium deficiencies depends on one's ability to adapt and conserve calcium. The relationship between calcium status and a particular disease state, such as osteoporosis, hypertension, or colon cancer, cannot be established until a reliable indicator of calcium status is found.