Human beings are most prone to calcium deficiency at two life stages and one special middle period.

The two life stages refer to childhood and old age. Children in the neonatal, infant and adolescent stages have high calcium demands to support growth and development. The elderly suffer from severe calcium loss and therefore require extra exogenous calcium supplements.

The special middle period covers pregnancy and lactation for women, as they need to supply nutrients for both themselves and their babies, calling for additional calcium intake.

Besides, patients with conditions that impair calcium absorption or accelerate calcium excretion, such as gastrointestinal disorders and diabetes, also need calcium supplements together with active treatment of underlying illnesses.

The Optimal Time for Calcium Intake Is Before Bed

Research on human calcium metabolism confirms that bedtime is the best time of day to take calcium supplements.

Three daily meals supply 400 to 500 milligrams of calcium. During the day, the body’s calcium regulatory system eliminates excess calcium via urine, while calcium from food replenishes blood calcium to keep its balance.

At night, calcium excretion through urine continues, yet no calcium can be obtained from food. To offset the lost urinary calcium, the bloodstream draws calcium from the body’s calcium reserve — bones. This mechanism explains why most calcium in morning urine originates from bone tissue.

In addition, calcium-regulating hormones have different secretion rhythms day and night. Blood calcium concentration is generally lower at night and higher during daytime. Nocturnal hypocalcemia stimulates parathyroid hormone secretion and accelerates bone calcium breakdown. Taking calcium supplements before sleep provides sufficient calcium at night and prevents the body from depleting bone calcium storage.

Milk, calcium-rich foods or calcium supplements can be taken before bedtime.

Drink Plenty of Water While Supplementing Calcium

Doctors always advise patients to drink adequate water when prescribing calcium supplements.

Calcium absorption depends on solubility and calcium source. Most calcium supplements are slightly soluble or soluble calcium salts. More water improves calcium solubility to a certain extent and boosts absorption efficiency. Hence, sufficient water is the ideal companion for calcium supplementation.