Thorne

Vitamin D3 (Liquid), 1 fl oz

Size: 30 Milliliters

May be a fit for

  • Adults seeking liquid D3 dosing flexibility without capsule swallowing
  • Practitioners titrating precise vitamin D3 levels in clinical protocols
  • Those with fat malabsorption who may benefit from liquid D3 delivery
$24.99

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LiquidFormat
1 fl ozPack size
The essentials

A closer look.

Thorne's Vitamin D3 Liquid delivers cholecalciferol, the same form your body synthesizes from sunlight, in a flexible liquid format that allows precise dose adjustments. It supports calcium absorption, bone density maintenance, and immune function, making it well-suited for adults who prefer to avoid capsules or need customizable dosing.

Why It's Worth Considering: Thorne formulates to NSF Certified for Sport standards with minimal excipients; the liquid format enables easy titration under practitioner guidance, which is particularly useful when optimizing individual D3 levels.

Inside the formula

Product details

Who it may suit

May be a fit for

  • Adults seeking liquid D3 dosing flexibility without capsule swallowing
  • Practitioners titrating precise vitamin D3 levels in clinical protocols
  • Those with fat malabsorption who may benefit from liquid D3 delivery
  • Older adults supporting bone density and immune function with D3

Considerations

  • Hypercalcemia (elevated blood calcium)
  • Sarcoidosis or other granulomatous diseases
  • Severe kidney disease without medical supervision
  • Taking thiazide diuretics (monitor calcium)
Compatibility & interactions

Works Well With

Magnesium
Magnesium is required for vitamin D activation
Vitamin K2
K2 directs calcium to bones
Omega-3
Both support immune function

Take Separately From

No significant interactions identified. Always consult your healthcare provider.

What to expect over time
Week 1–2

Serum Levels Rise

Measurable increase in 25(OH)D

Week 4–8

Immune Support

Improved innate immune function

Month 2–3

Mood & Energy

Reduced fatigue and improved mood

Month 3–6

Optimal Range

Target 50-80 ng/mL achieved

Based on clinical studies on vitamin D3 supplementation. Response varies by baseline levels, body weight, and skin tone.

Compare the options

Compare Vitamin D Forms

D3 vs D2 vs D3+K2

FeatureD3 (Cholecalciferol)D2 (Ergocalciferol)D3 + K2 Combo
SourceAnimal (lanolin/lichen)Plant/fungalAnimal + bacterial
Potency87% more effective at raising serum DBaselineSame as D3 + K2 synergy
Half-Life~2-3 weeks~2-3 days~2-3 weeks
Best ForGeneral supplementationVegan-only optionBone + cardiovascular health
EvidenceStrong (gold standard)ModerateStrong (synergistic)
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Good to know

A few useful answers.

Research & further reading

More category questions

How much vitamin D3 should I take daily?

Most functional medicine practitioners recommend 5,000 IU daily for adults with normal BMI, and up to 10,000 IU for those with obesity or severe deficiency. The Endocrine Society recommends maintaining serum 25(OH)D levels between 40-60 ng/mL. Test your levels every 3-6 months.

Is vitamin D3 better than D2?

Yes. D3 (cholecalciferol) is 87% more effective at raising and maintaining serum vitamin D levels compared to D2 (ergocalciferol). D3 also has a longer half-life. D2 is only preferred by strict vegans who cannot use lanolin-sourced D3 — lichen-based D3 is the vegan alternative.

Should I take vitamin D3 with vitamin K2?

Yes, especially at doses above 2,000 IU. Vitamin D3 increases calcium absorption from food. Without K2, that calcium can deposit in arteries instead of bones. K2 (MK-7 form) activates osteocalcin (puts calcium in bones) and matrix GLA protein (keeps calcium out of arteries).

Can I take too much vitamin D?

Toxicity is rare below 10,000 IU/day in healthy adults but possible with chronic high-dose use without monitoring. Symptoms of excess include hypercalcemia (nausea, kidney stones, confusion). Always pair high-dose D3 with K2 and test 25(OH)D levels every 3-6 months.

When is the best time to take vitamin D3?

Take with your largest meal containing fat — D3 is fat-soluble and absorption increases 30-50% when taken with dietary fat. Morning or afternoon is preferred over evening, as some studies suggest late-night D3 may interfere with melatonin production.

How long does it take for vitamin D levels to increase?

Serum 25(OH)D typically rises within 1-2 weeks of supplementation. Reaching optimal range (50-80 ng/mL) takes 2-3 months at 5,000 IU/day from a deficient baseline. Higher loading doses (10,000 IU for 8 weeks then maintenance) can accelerate this.

Supplement information is provided for education and is not a substitute for personalized medical advice. Supplements are not intended to diagnose, treat, cure or prevent disease. Read the current product label before use.

Thorne - Vitamin D3 (Liquid), 1 fl oz