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Vitamins & Minerals

Vitamin D Calculator

Calculate your daily vitamin D needs based on age, skin type, and sun exposure. Free vitamin D calculator with food sources and supplement guidance.

Vitamin D at a glance

Every number this page produces traces back to the reference values in the lead paragraph - the calculator adjusts WHO-table guidance by life stage, it never substitutes different source data.

Calculate your daily vitamin D needs based on age, skin type, and sun exposure. Free vitamin D calculator with food sources and supplement guidance. The page is written for people who log their food: the vitamin D target sits next to your diary totals in the same units your food entries use, so you can see how close today came without extra math.

Calculate your vitamin D needs

Your results

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Daily IU
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Sun (min/day)

About the Vitamin D Calculator

This calculator provides evidence-based targets and interpretation based on current nutritional science and dietary guidelines. The formulas and reference ranges used are drawn from authoritative sources including the National Academies of Sciences, Engineering, and Medicine (Dietary Reference Intakes), the USDA Dietary Guidelines for Americans 2025-2030, and peer-reviewed research published in journals such as the American Journal of Clinical Nutrition, the New England Journal of Medicine, and JAMA.

How this calculator works

The calculator uses validated formulas that account for individual factors such as age, sex, body weight, and activity level. The results are personalized to your inputs and include interpretation categories (low, normal, high) based on established clinical or nutritional reference ranges. Always interpret results in the context of your overall health, diet, and lifestyle, a single number rarely tells the full story.

Practical guidance

Use this calculator as a starting point for understanding your nutritional needs or health metrics. The results are educational, not diagnostic, always discuss significant findings with your healthcare provider before making changes to your diet, supplement regimen, or medication. For best results, recalculate periodically as your body composition, activity level, or health status changes. Track trends over time rather than focusing on single measurements, as day-to-day variation is normal and expected.

Evidence base and limitations

All nutritional targets are based on population-level recommendations that apply to most healthy individuals. Individual needs may vary based on genetics, medical conditions, medications, pregnancy, lactation, and other factors. The calculators do not replace professional medical or nutritional advice. If you have a chronic health condition, are pregnant or breastfeeding, or take medications that affect nutrient metabolism, consult a registered dietitian or physician for personalized guidance.

Editorial and formula review
Formulas verified against published peer-reviewed sources Last verified

Formula sources, population limits, and references for this vitamin and mineral calculator are documented in our public methodology. Read the methodology · Medical disclaimer

Frequently asked questions

The RDA is 600 IU for adults under 70, 800 IU for those over 70. Many experts recommend 1,500-2,000 IU/day.
Yes, in summer at latitudes below 37°N, 10-30 minutes of midday sun 2-3x/week is typically sufficient.
Common symptoms: fatigue, bone pain, muscle weakness, frequent infections, depression.
Yes. The upper limit is 4,000 IU/day. Long-term excessive intake can cause hypercalcemia and kidney stones.
Fatty fish (salmon 526 IU/3.5oz), cod liver oil (1,360 IU/tbsp), egg yolks (41 IU), fortified milk (115 IU/cup).