Quick answer
NIH sets vitamin D upper limits by age: 63 mcg (2,500 IU) a day at ages 1 to 3, 75 mcg at 4 to 8 and 100 mcg from age 9. Too much can raise blood calcium. NIH says breast milk alone does not meet an infant's needs. Ask your doctor before giving a child vitamin D.1,2
Key facts
- NIH's upper limits for vitamin D are 25 mcg (1,000 IU) a day to age 6 months, 38 mcg (1,500 IU) at 7 to 12 months, 63 mcg (2,500 IU) at 1 to 3 years, 75 mcg (3,000 IU) at 4 to 8 and 100 mcg (4,000 IU) at 9 to 18.1
- NIH's recommended amount is 10 mcg (400 IU) a day from birth to 12 months and 15 mcg (600 IU) a day from ages 1 to 18.1
- NIH says high vitamin D levels are almost always caused by consuming too much from supplements, and that sun on the skin cannot cause toxicity.1,2
- NIH says prolonged exclusive breastfeeding without vitamin D supplementation can cause rickets in infants.2
- The Endocrine Society's 2024 guideline suggests vitamin D supplements for children and teens, without recommending a specific dose.3
Vitamin D limits and recommended amounts by age
| Age | Recommended amount | Upper limit from all sources |
|---|---|---|
| Birth to 6 months | 10 mcg (400 IU) | 25 mcg (1,000 IU) |
| 7 to 12 months | 10 mcg (400 IU) | 38 mcg (1,500 IU) |
| 1 to 3 years | 15 mcg (600 IU) | 63 mcg (2,500 IU) |
| 4 to 8 years | 15 mcg (600 IU) | 75 mcg (3,000 IU) |
| 9 to 13 years | 15 mcg (600 IU) | 100 mcg (4,000 IU) |
| 14 to 18 years | 15 mcg (600 IU) | 100 mcg (4,000 IU) |
The upper limits count vitamin D from foods, drinks and supplements together. NIH notes that a health care provider may recommend doses above these limits for a period of time to treat a deficiency, which is a medical decision for an individual child.1
What too much vitamin D can do
Too much vitamin D raises blood calcium. Signs include nausea, vomiting, muscle weakness, confusion, pain, loss of appetite, dehydration, passing a lot of urine, great thirst and kidney stones. They are linked to blood levels far above normal, usually over 150 ng/mL (375 nmol/L).1,2
NIH says very high levels are almost always caused by consuming excessive amounts of vitamin D from dietary supplements, including products made with manufacturing errors or taken in the wrong amount. It adds that the skin limits how much vitamin D it makes, so sunshine cannot cause toxicity.1,2
Why NIH also names too little
Low vitamin D matters in children too. NIH says deficiency in children shows up as rickets, a disease in which the bones become soft and deformed, and that prolonged exclusive breastfeeding without vitamin D supplementation can cause it. NIH reports that the American Academy of Pediatrics recommends 10 mcg (400 IU) a day for exclusively and partially breastfed infants starting shortly after birth, and also for infants who take less than about 1,000 mL a day of fortified formula or milk.1,2
The Endocrine Society's 2024 guideline suggests against taking more than the recommended intake for healthy adults aged 19 to 74, and against routine blood testing. It suggests supplements for children and teens, adults 75 and older and during pregnancy, without recommending a specific dose.2,3
Who should ask their doctor
Ask your doctor or pediatrician before giving a child or teen vitamin D, and ask before adding drops, gummies or a multivitamin on top of one another, since NIH counts every source toward the limit. Ask too if the child has a condition that affects calcium, kidney disease or kidney stones, or takes steroid tablets or other medicines, which NIH names as able to affect vitamin D status or calcium.1,2
Questions people ask
Is vitamin D safe for teens?
NIH's upper limit for ages 9 to 18 is 100 mcg (4,000 IU) a day from all sources, and its recommended amount is 15 mcg (600 IU). Ask your doctor before a teen takes a supplement.1
Is vitamin D good for teens?
NIH gives a recommended amount of 15 mcg (600 IU) for ages 1 to 18, and the Endocrine Society's 2024 guideline suggests supplements for children and teens without giving a dose. A doctor can say whether a teen needs one.1,3
Is vitamin D3 safe for kids?
NIH's limits cover vitamin D from all sources and do not separate D2 from D3. They are 63 mcg (2,500 IU) at ages 1 to 3 and 75 mcg (3,000 IU) at ages 4 to 8.1
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Sources
- Office of Dietary Supplements, National Institutes of Health. Vitamin D: Fact Sheet for Consumers. Updated November 8, 2022. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. Updated June 27, 2025. Opened 2026-10-07.
- Demay MB, et al. Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2024;109(8):1907-1947. Opened 2026-10-01.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.