How much Vitamin D should you take?
Most adults need 600–800 International Units (IU), or 15–20 micrograms (mcg), of vitamin D per day to support bone and immune health. The exact amount depends on your age, overall health, and how much sunlight you get. The safe upper limit for adults is 4,000 IU (100 mcg) per day—going above this may cause harm and should only be done on a doctor’s advice. Make sure to talk with your healthcare provider if you have specific health conditions or concerns about deficiency.
Recommended Daily Allowances by Age
Vitamin D daily needs can vary across life stages. Here’s a table showing the Recommended Dietary Allowance (RDA) for vitamin D. IU (International Units) and mcg (micrograms) are two ways to measure vitamin D—1 mcg = 40 IU.
| Age Group | RDA (IU) | RDA (mcg) |
|---|---|---|
| Infants (0–12 months) | 400 | 10 |
| Children (1–13 years) | 600 | 15 |
| Teenagers (14–18 years) | 600 | 15 |
| Adults (19–70 years) | 600 | 15 |
| Adults (71+ years) | 800 | 20 |
| Pregnant / Breastfeeding | 600 | 15 |
Safe Upper Limit for Vitamin D
Below are the maximum safe daily amounts, known as the Tolerable Upper Intake Level (UL). Only exceed these amounts under medical supervision.
| Age Group | Upper Limit (IU) | Upper Limit (mcg) |
|---|---|---|
| Infants (0–6 months) | 1,000 | 25 |
| Infants (7–12 months) | 1,500 | 38 |
| Children (1–3 years) | 2,500 | 63 |
| Children (4–8 years) | 3,000 | 75 |
| Children & Adults (9+ years) | 4,000 | 100 |
Can You Take Too Much Vitamin D?
Yes. Taking too much vitamin D can cause toxicity, leading to high calcium levels (hypercalcemia). This may result in kidney stones, irregular heartbeat, and other health complications.
Toxicity symptoms include:
- Nausea and vomiting
- Weakness and fatigue
- Frequent urination
- Thirst
- Confusion
- Dehydration
When to Call a Doctor
If you experience persistent vomiting, confusion, extreme thirst, or severe muscle weakness after taking vitamin D supplements, contact your doctor promptly.
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How Much Vitamin D From Sunlight?
You can typically make enough vitamin D by getting 5–30 minutes of midday sun (10 a.m. to 4 p.m.), at least 2–3 times a week on your face, arms, and legs, without sunscreen.
Factors that affect vitamin D production:
- Skin tone (darker skin makes less vitamin D)
- Latitude (farther from the equator means less UVB)
- Use of sunscreen
- Air pollution
- Season (little or no UVB in winter in some regions)
- Age (older adults produce less from the sun)
Sunlight may not provide enough vitamin D for many people during winter or for those with limited outdoor time.
How Much Vitamin D Is in Foods?
While some foods are good sources, most people cannot meet their daily vitamin D needs from diet alone.
| Food | Vitamin D (IU/serving) | Vitamin D (mcg/serving) |
|---|---|---|
| Wild salmon (100 g, cooked) | 320–2,200 | 8–55 |
| Fortified milk (1 cup) | 120 | 3 |
| Eggs (2 large) | 88 | 2.2 |
| Fortified cereal | 40–80 | 1–2 |
| Raw white mushrooms exposed to UV light (½ cup) | 366 | 9.2 |
Special Considerations
While the general vitamin D guidelines work for most healthy adults, certain groups have unique needs or face a higher risk of deficiency. Factors like pregnancy, age, chronic health conditions, or limited sun exposure can mean you need more—or less—vitamin D than the average recommendation. In these cases, professional guidance is especially important to determine the safest and most effective intake.
- Pregnancy and breastfeeding: RDA is 600 IU (15 mcg), but your doctor may recommend more in specific cases.
- Older Adults: Reduced skin synthesis; supplement or fortified foods may be needed.
- Medical Conditions: People with obesity, malabsorption disorders, or diagnosed deficiency often need extra vitamin D—testing is recommended before high-dose supplementation.
If you’re taking over-the-counter high doses, ask your healthcare provider about blood tests to check your levels.
Key Takeaways
- Most adults need 600–800 IU (15–20 mcg) daily.
- Don’t exceed 4,000 IU (100 mcg) without medical advice.
- Sun, food, and supplements can all contribute to your vitamin D intake.
- Individual needs depend on age, sun exposure, diet, pregnancy/breastfeeding, and medical conditions.
Always talk to your healthcare provider before starting high-dose supplements.
References
- Jakobsen, J., Smith, C., Bysted, A., & Cashman, K. D. (2019). Vitamin D in Wild and Farmed Atlantic Salmon (Salmo Salar)-What Do We Know?. Nutrients, 11(5), 982. https://doi.org/10.3390/nu11050982
- Johnson, L. E. (2024). Vitamin D excess (vitamin D toxicity). MSD Manual Consumer Version. https://www.msdmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-d-excess
- Marcinowska-Suchowierska, E., Kupisz-Urbańska, M., Łukaszkiewicz, J., Płudowski, P., & Jones, G. (2018). Vitamin D Toxicity-A Clinical Perspective. Frontiers in endocrinology, 9, 550. https://doi.org/10.3389/fendo.2018.00550
- Office of Dietary Supplements. (n.d.). Vitamin D fact sheet for health professionals. National Institutes of Health. Retrieved August 11, 2025, from https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
- Office of Dietary Supplements. (2023). Vitamin D fact sheet for consumers. National Institutes of Health. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
- Wacker, M., & Holick, M. F. (2013). Sunlight and Vitamin D: A global perspective for health. Dermato-endocrinology, 5(1), 51–108. https://doi.org/10.4161/derm.24494
Read next
Vitamin D Deficiency: What are the symptoms?
Vitamin D deficiency symptoms can vary from subtle to severe and often develop gradually. Early signs include fatigue, bone or back pain, muscle weakness or cramps, frequent illness, and hair loss.
Continue reading
How long does it take for vitamin D to work?
Generally, it takes a few weeks of taking daily vitamin D supplements for vitamin D levels in the body to rise. Each 1,000 IU of vitamin D3 daily is expected to raise blood levels of 25(OD)D by 10 ng/ml after a few weeks. But it may take months to resolve symptoms of severe vitamin D deficiency such as rickets in children. It depends on how low your vitamin D levels were in the first place and some individual factors. Obesity, polluted environments, and malabsorption syndromes (such as Crohn’s disease) are just some factors that can increase the time it takes for vitamin D levels to work. Continue reading
How can I raise my vitamin D levels quickly?
You can raise your vitamin D levels quickly in three main ways, but it can take up to a week for increased vitamin D intake or exposure to be reflected in a vitamin D blood test: increasing your intake of foods that are naturally rich in vitamin D or fortified with vitamin D, taking a vitamin D supplement, or getting outside and exposing your skin to sunlight (although experts do not recommend this without sun protection). Continue reading
See also:
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