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Vitamin D3

Cholecalciferol (D3), Ergocalciferol (D2), Calcifediol, Calcitriol

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Meta Information

ID:vitamin-d
Name:Vitamin D3
Schema Version:1.5

Alternate Names

  • Cholecalciferol (D3)
  • Ergocalciferol (D2)
  • Calcifediol
  • Calcitriol

Active Compound

Cholecalciferol

Intervention Type

therapeutic_agent

Delivery

Route:
oral
Scope:
  • systemic

Regulatory Status

  • us:dietary_supplement
  • eu:food_supplement
  • us:rx_drug
  • eu:rx_drug

Indication

Focus:
healthspan
Description:
Correcting deficiency and maintaining optimal levels for immune function, bone health, and cellular regulation.

Typical Protocol

  • Daily supplementation of 1,000-4,000 IU of Vitamin D3 is common to maintain optimal levels.
  • Blood levels (25-hydroxyvitamin D) are often targeted to be between 30-60 ng/mL.
  • Higher loading doses may be used initially to correct a severe deficiency under medical supervision.

Expected Cost Mean

Low Cost:
5
High Cost:
15
Cost Type:
monthly
Description:
Widely available over-the-counter oral supplements; generally not covered by insurance.

Summary

Vitamin D is a fat-soluble prohormone that primarily regulates calcium and phosphorus metabolism, which is critical for bone health. Its receptor (VDR) is present in nearly every cell type, allowing it to modulate the expression of hundreds of genes involved in immune function, inflammation, and cell growth. Correcting widespread deficiency is a key healthspan strategy to support skeletal integrity and immune competence, potentially reducing the risk of various age-related conditions.

Purpose

A prohormone essential for bone health, immune function, and cellular regulation.

Card Summary

A fat-soluble vitamin and prohormone crucial for calcium homeostasis, immune modulation, and bone density, primarily obtained through sun exposure and supplementation.

Drug Class

null

Drugs In Class

  • vitamin-d3
  • vitamin-d-supplementation

Impact

Score:
7.5
Justification:
Correcting common deficiency has a foundational impact on bone, immune, and metabolic health.

Evidence

Grade:
A
Score:
9
Justification:
Extensive RCTs and meta-analyses confirm its role in bone health and deficiency correction.

Safety

Score:
3
Justification:
Very safe at recommended doses; toxicity is rare and requires extremely high intake.

Flags

  • Toxicity (hypercalcemia) can occur with prolonged, very high doses (>10,000 IU/day).
  • As a fat-soluble vitamin, it should be taken with a source of fat for optimal absorption.
  • May interact with certain medications, including steroids, statins, and thiazide diuretics.
  • Optimal levels should be confirmed with a blood test (25-hydroxyvitamin D).

Verdict

Essential for correcting deficiency; a foundational supplement for most individuals.

Created

2026-05-05T22:02:34.756821Z

Ai Model

Gemini 2.5 Pro (High)