Browse/Essential Vitamin
Essential Vitamin

Vitamin D3 (Cholecalciferol)

01 / OVERVIEW

What this compound does

WHAT IT DOES

Vitamin D3 helps your body absorb calcium, which is essential for strong bones and teeth. It also supports your immune system and can improve mood. Many people get vitamin D from sunlight, but if you don't get enough, a supplement can help keep your body functioning well.

KEY BENEFITS
Supports bone health
Boosts immune function
Improves mood
Enhances muscle strength
BEST FOR
  • • People with limited sun exposure
  • • Older adults at risk of bone loss
  • • Individuals with mood fluctuations
WHAT TO EXPECT

You may start to notice improvements in mood and energy levels within a few weeks of taking vitamin D3. It can take longer to see effects on bone health, often several months.

WHO SHOULD AVOID THIS
  • • People with certain kidney disorders
  • • Those with hypercalcemia
  • • Individuals on specific medications affecting calcium levels
MYTHS & FACTS
Myth: You can get enough vitamin D from diet alone.
Fact: While some foods contain vitamin D, it is challenging to obtain sufficient amounts without sunlight exposure or supplementation.
Myth: Vitamin D is only important for bone health.
Fact: Vitamin D also plays a significant role in immune function and has been linked to mood regulation.
At a glance
Typical dose
1000-5000 IU/day based on labs
Evidence
—
Studies indexed2
How it's made

Production details below.

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03 / DOSAGE

How much, when

MAINTENANCE

1000-5000 IU/day based on labs

lab guided

TIMING

Vitamin D3 (Cholecalciferol) — Morning dose

Take with food (fat-containing meal) for fat-soluble absorption

02 / EVIDENCE

Peer-reviewed studies

  • PMID: 21646368

    Deficiency correction

    Supplementation increases 25(OH)D levels in deficient adults.

    A
  • PMID: 28202713

    Respiratory infection risk

    Meta-analysis suggests modest benefit in some populations.

    B
  • PMID 21646368 · 2011Systematic Review

    Vitamin D and Immune Function: A Systematic Review

    Vitamin D modulates both innate and adaptive immune responses.

    A
  • PMID 28202713 · 2017 · n=10933Meta-Analysis

    Vitamin D Supplementation for Prevention of Respiratory Infections: Meta-Analysis

    Vitamin D supplementation reduced risk of acute respiratory infections, especially in deficient individuals.

    A
  • PMID 12499343 · 2003 · n=67RCT

    Dose-Response Relationship of Vitamin D3 Supplementation

    1000 IU/day raised 25(OH)D levels by approximately 10 ng/mL over 3 months.

    A
  • PMID 16825677 · 2006 · n=445RCT

    Vitamin D and Bone Mineral Density in Postmenopausal Women

    Vitamin D with calcium improved bone mineral density at the hip and spine.

    A
  • PMID 31567003 · 2019 · n=55844Cross-sectional

    Vitamin D Deficiency: Global Prevalence and Population Trends

    Over 40% of adults worldwide are vitamin D deficient.

    A
04 / INTERACTIONS

Medicine interactions

  • Thiazide diuretics· diuretic

    Thiazides can increase calcium levels, potentially leading to hypercalcemia when combined with vitamin D3.

    → Monitor calcium levels closely.

    HIGH

  • Corticosteroids· anti-inflammatory

    Corticosteroids can reduce vitamin D metabolism, leading to lower calcium absorption.

    → Consider adjusting vitamin D3 dosage.

    MODERATE

  • Anticonvulsants· antiepileptic

    Certain anticonvulsants can decrease vitamin D levels, necessitating higher supplementation.

    → Monitor vitamin D status regularly.

    MODERATE

This page is a reference summary, not a prescription. Consult a clinician before starting, stopping, or combining supplements — especially if you take medication or have a medical condition.