​Vitamin D3 (cholecalciferol) at a daily intake of 10 micrograms (mcg), equivalent to 400 International Units (IU), is essential for maintaining bone health, supporting immune function, and facilitating calcium and phosphorus absorption. This dosage aligns with recommendations from health authorities, such as the UK's National Health Service (NHS), https://thevitashope.com/p/vit....amin-d3-supports-imm