Vitamin D

About Vitamin D

Essential for calcium absorption, bone health, immune regulation, and gene expression. Vitamin D3 (cholecalciferol) is significantly more effective than D2 (ergocalciferol) at raising and maintaining blood levels, making it the preferred supplemental form. As a fat-soluble vitamin, absorption improves when taken with a meal containing fat. Deficiency is widespread, especially in northern latitudes and among people with darker skin tones.

What Vitamin D supports

• 🦴Builds strong bones
• 🛡️Supports immune health
• 💪Maintains muscle function

How much Vitamin D to take

Clinical studies typically use 1000–5000 IU of Vitamin D. Clinical consensus supports 1000–5000 IU/day; RDA of 600 IU is considered conservative.

RDA

600 IU

Upper limit (UL)

4000 IU

Effective range

1000–5000 IU

Forms of Vitamin D compared

• Cholecalciferol (D3)Premium
  Identical to the form your skin makes from sunlight.
• Ergocalciferol (D2)Budget
  D2 — less effective than D3

Clinical evidence

Strong clinical evidence. Meta-analyses of 81+ trials confirm bone health benefits; immune and mood claims have mixed results