For women aged 20-40, it is best to supplement calcium twice a day, and the best oral time is 10 in the morning and 2 pm, because the metabolic rate is at its best, which is the best absorption time for calcium supplementation in the body, and the hormone level in the body is the most vigorous. Therefore, for women, because the secretion of estrogen and progesterone in the body is relatively high and is regulated by internal factors, it is necessary to choose the best time to eat calcium tablets in order to achieve good absorption effect.