Daily Vitamin D Intake Checker
Vitamin D status depends on supplements, diet, and sun. Estimate total IU intake and compare it to your life-stage recommendation.
Daily Inputs
Estimate only—cloud cover, latitude, and skin tone affect synthesis.
Vitamin D Intake Summary
Total vitamin D
2800 IU
≈ 70 μg
Percent of RDA
466.7%
Sun exposure estimate
About 1500 IU attributed to sun (15 minutes). Adjust for latitude, skin tone, and time of year.
RDA for women aged 32 is 600 IU (15 μg).
How to Use This Calculator
Contrast diet, supplements, and sun
Vitamin D can come from several sources. Logging each helps you avoid deficiency or excessive supplementation.
Be mindful of seasonal changes
Sun-driven vitamin D production drops in winter or at high latitudes. Reassess inputs when daylight changes.
Confirm status with lab tests
Serum 25(OH)D testing is the gold standard. Use this calculator for planning, then validate with healthcare providers.
Formula
Total IU = Supplements + Fortified foods + Natural foods + Sun estimate
Vitamin D (μg) = IU ÷ 40
Percent RDA = (Total IU ÷ Recommended IU) × 100
- Sun estimate is approximate—melanin, SPF, cloud cover, and latitude all influence production.
- RDA assumes minimal sun exposure; adequate sun can reduce dietary needs.
- Upper tolerable limit (UL) for adults is 4,000 IU/day without medical supervision.
Full Description
Vitamin D regulates calcium absorption, bone mineralisation, and immune modulation. Modern indoor lifestyles and sunscreen use limit cutaneous synthesis, making diet and supplements critical. This calculator helps you reconcile all sources to hit recommended targets without surpassing upper limits.
Vitamin D metabolism interacts with vitamin K2, magnesium, and calcium balance. Consult healthcare professionals before high-dose regimens, especially if you have kidney disease or take medications affecting vitamin D metabolism.
Frequently Asked Questions
How much sun do I really need?
Fair-skinned individuals may need 10–20 minutes midday; darker skin tones require more. Winter sun at high latitudes may produce little vitamin D.
Should I take vitamin D3 or D2?
Vitamin D3 (cholecalciferol) typically raises blood levels more effectively than D2. Follow your healthcare provider’s guidance.
Can I take vitamin D without food?
It’s fat-soluble. Absorption improves when taken with meals containing dietary fat.
What if my blood levels are low?
Your clinician may prescribe higher doses temporarily. Reassess with lab tests after the repletion phase.