Calculate your daily vitamin D dose
This free calculator estimates how much vitamin D-3 to take each day from your age, sun exposure, skin tone, body weight, and risk factors — then points you to the matching 1000, 2000, or 5000 IU strength. Answer the quick questions below; your estimate updates instantly, with built-in safety checks.
Your estimated daily dose
2000 IU of vitamin D-3 per day
Educational estimate only, not medical advice. Talk to your doctor or pharmacist before starting vitamin D, especially if you take medication or have a health condition.
Vitamin D dosage depends on how much your skin makes from sunlight and how much you get from food — both of which vary with where you live, your skin tone, your age, and the season. Because most people fall short, a daily supplement of 1000 to 5000 IU of vitamin D-3 is common, with the right strength depending on your sun exposure, body weight, and whether a blood test has shown you are low.
Quick answer: The vitamin D RDA is 600 IU a day for adults up to 70 and 800 IU after that, but many adults with little sun take 1000 to 2000 IU of vitamin D-3 to maintain a healthy level. Higher doses such as 5000 IU are used to correct a confirmed deficiency, and the supplemental upper limit for adults is 4000 IU a day unless a clinician advises more.
Key Takeaways
- Vitamin D-3 (cholecalciferol) raises and holds your blood level better than D-2.
- 1 capsule a day is the dose — the strengths are 1000, 2000, or 5000 IU (25, 50, or 125 mcg).
- Less sun, darker skin, older age, and a larger body all push your need higher.
- 5000 IU is above the 4000 IU daily upper limit — use it only to fix a tested-low level, with a clinician.
- Vitamin D is fat-soluble, so take it with your largest meal and recheck your level in 2 to 3 months.
How the calculator works
Vitamin D is measured in international units (IU) or micrograms (mcg), where 1 mcg equals 40 IU, so 1000 IU is 25 mcg and 5000 IU is 125 mcg. The tool starts from the established daily requirement for your age, then raises the suggested supplement when factors that lower your vitamin D stack up — little sun, darker skin, a higher body weight, a low-vitamin-D diet, or malabsorption.[1]Vitamin D Fact Sheet for Health Professionals — NIH Office of Dietary Supplements View source
It keeps the routine recommendation at or below the 4000 IU supplemental upper limit. It only suggests 5000 IU when you tell it a blood test showed your level was low, because correcting a true deficiency is the one case where a short course above the upper limit is appropriate — and even then it should be done with your clinician.
| Group | Daily requirement (RDA) | Supplement upper limit |
|---|---|---|
| Adults 19–70 | 600 IU (15 mcg) | 4000 IU (100 mcg) |
| Adults 71+ | 800 IU (20 mcg) | 4000 IU |
| Pregnancy / breastfeeding | 600 IU (15 mcg) | 4000 IU |
| Children 1–18 | 600 IU (15 mcg) | 2500–4000 IU |
A blood test (25-hydroxyvitamin D) is the only way to know your level: below 20 ng/mL (50 nmol/L) is deficient, 20 to 30 ng/mL is on the low side, and above 50 ng/mL can be too high. Values are set by the National Academy of Medicine and NIH.[1]Vitamin D Fact Sheet for Health Professionals — NIH Office of Dietary Supplements View source
Going deeper on vitamin D dosing
This calculator gives you a sensible starting strength. For the clinical detail behind it — what a deficiency feels like, how to read a 25-hydroxyvitamin D result, and how fast levels respond — read our guide to vitamin D deficiency: symptoms, causes, testing, and treatment.
If you would rather raise your level through sunlight and food first, the best sources of vitamin D from sun, food, and supplements walks through how much each one realistically provides.
Vitamin D-3 — Vegan Capsules
One easy capsule a day, in three strengths so you can match the dose above: 1000 IU, 2000 IU, and 5000 IU. USA-made, vegan, 60 capsules per bottle.
Shop Vitamin D-3 →Frequently Asked Questions
How much vitamin D should I take per day? +
The RDA is 600 IU for adults up to 70 and 800 IU after that, counting food and sun. Because most people get little, a daily vitamin D-3 supplement of 1000 to 2000 IU is common for maintenance. Stay at or below the 4000 IU supplemental upper limit unless your clinician advises more.
Should I take 1000, 2000, or 5000 IU? +
1000 IU suits people who get regular sun and have no risk factors. 2000 IU fits most adults with limited sun, darker skin, older age, or a higher body weight. 5000 IU is a correction dose for a blood test that came back low, and is best used short-term with your clinician.
What is the difference between IU and mcg? +
They measure the same thing on different scales: 1 microgram (mcg) of vitamin D equals 40 IU. So 1000 IU is 25 mcg, 2000 IU is 50 mcg, and 5000 IU is 125 mcg. Labels may show either, so check which unit you are reading.
Can I take too much vitamin D? +
Yes. The supplemental upper limit for adults is 4000 IU a day. Taking very high doses for a long time can raise blood calcium and cause nausea, kidney problems, and an irregular heartbeat. A blood level above 50 ng/mL is considered too high.
Why do darker skin and less sun mean I need more? +
Your skin makes vitamin D from midday sun, but melanin in darker skin filters that sunlight, so it produces less from the same exposure. Living far from the equator, spending time indoors, and winter all cut production too, which raises how much you need from a supplement.
Should I take vitamin D with food? +
Yes. Vitamin D is fat-soluble, so taking it with your largest meal of the day, which usually has some fat, improves absorption. Any time of day works, so pick the meal you are most likely to remember it with.
How long until my vitamin D level improves? +
Blood levels rise gradually. With a consistent daily dose, most people see a meaningful change in about 2 to 3 months, which is why a recheck is usually scheduled then. Take it every day rather than large weekly doses for a steadier level.
Do I need a blood test before supplementing? +
A maintenance dose of 1000 to 2000 IU is widely considered safe without testing. But a 25-hydroxyvitamin D test is the only way to know your actual level, and you should test before using a high 5000 IU dose so you and your clinician can confirm it is needed.
Is vitamin D-3 better than D-2? +
For most people, yes. Vitamin D-3 (cholecalciferol) is the same form your skin makes, and studies show it raises and maintains blood levels more effectively than D-2 (ergocalciferol). Our capsules use D-3.
Can I take vitamin D during pregnancy? +
The pregnancy RDA is 600 IU a day, and many prenatal routines include 1000 to 2000 IU. Avoid high doses unless your OB or midwife recommends them based on a blood test. Always confirm your exact dose with your maternity provider.
What medications interact with vitamin D? +
Thiazide diuretics and digoxin can interact with vitamin D and calcium, steroids can lower vitamin D, and weight-loss drugs such as orlistat can reduce absorption. If you take any of these, ask your pharmacist before starting a supplement.
Is this vitamin D vegan? +
Yes. Remedy's Nutrition Vitamin D-3 comes in vegan capsules, with 60 capsules per bottle. One capsule a day means a single bottle lasts about two months.
Medical Disclaimer
This calculator provides general educational estimates only and is not medical advice, a diagnosis, or a treatment plan. The results are based on population reference intakes and cannot account for your full medical history, lab values, medications, or individual needs.
Always talk to a doctor or pharmacist before starting or changing a vitamin D supplement, and in particular if you:
- have sarcoidosis, high blood calcium, kidney stones, an overactive parathyroid, or any chronic condition;
- are pregnant or breastfeeding;
- take prescription medication, including thiazide diuretics or digoxin;
- are choosing a dose for anyone under 18 years of age.
Do not exceed 4000 IU per day of supplemental vitamin D without medical supervision. If you develop nausea, vomiting, weakness, frequent urination, or confusion, stop taking vitamin D and seek medical care, as these can be signs of too much calcium.
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.