Last reviewed 2026-04-22 · How we verify

Vitamin D3 as "BABY D3"

Vitamin D3 acts as a steroid hormone precursor that regulates calcium and phosphate homeostasis and modulates immune function.

Vitamin D3 acts as a steroid hormone precursor that regulates calcium and phosphate homeostasis and modulates immune function. Used for Vitamin D deficiency prevention and treatment in infants and children, Support of bone health and calcium absorption in pediatric populations.

At a glance

Mechanism of action

Vitamin D3 (cholecalciferol) is converted in the liver to 25-hydroxyvitamin D and then in the kidneys to the active form 1,25-dihydroxyvitamin D, which binds to the vitamin D receptor (VDR) to regulate intestinal calcium absorption, bone mineralization, and immune cell differentiation. This mechanism supports skeletal health, calcium homeostasis, and immune regulation, making it essential for multiple physiological processes.

Approved indications

• Vitamin D deficiency prevention and treatment in infants and children
• Support of bone health and calcium absorption in pediatric populations

Common side effects

• Hypercalcemia (with excessive dosing)
• Hypercalciuria (with excessive dosing)
• Gastrointestinal upset (rare at therapeutic doses)

Key clinical trials

• The Effect of Vitamin D Replacement on Airway Reactivity, Allergy and Inflammatory Mediators in Exhaled Breath Condensate in Vitamin D Deficient Asthmatic Children (NA)

Primary sources

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