Taking Too Much: Overdose With Vitamins, Minerals and Herbs
What to do if someone has taken too much of a vitamin, mineral or herbal product, with official upper levels quoted by source and year. Poison Help is 1-800-222-1222 (US).
Content last updated . This page has not been medically reviewed.
Call 911 if the person has collapsed, has a seizure, has trouble breathing or cannot be woken. [1] Otherwise call Poison Help at 1-800-222-1222 (US) now, even if the person feels fine. [2] Do not induce vomiting. [1] If the extra pills were taken on purpose, call 911, and call or text 988 for emotional support. Poison Control says immediate evaluation by a healthcare provider, usually in an emergency room, is always advised when the intent is self-harm. [1] [3]
Keep this in mind: MedlinePlus says any substance can be poisonous if too much is taken. [4] "Natural" does not always mean "safe." [5]
Children first
Iron is the best-documented example. MedlinePlus says iron overdose is particularly dangerous for children, and that a severe overdose can happen if a child eats adult multivitamins such as prenatal vitamins. [6] The NHS (UK) says very high doses of iron can be fatal, particularly in children, so iron supplements should always be kept out of reach. [7] For other products, see A child swallowed a supplement or natural product, Iron overdose and child safety and Vitamin overdose in children.
Iron symptoms can seem to pass and then return: MedlinePlus says symptoms may go away in a few hours, then return after a day or later, and liver damage may occur several days after the ingestion. [6] That is why a call is worthwhile even when the person looks better.
Official upper levels, quoted
These are statements from one body, not goals and not advice for any reader. Whether a different amount is right for a person is for a clinician or pharmacist. The levels below are quoted from NHS (UK) vitamin and mineral pages last reviewed 3 August 2020.
| Nutrient | What too much can cause (source) | Level quoted by the NHS (UK, 2020) |
|---|---|---|
| Vitamin D | Over a long period, too much calcium in the body (hypercalcaemia), which can weaken bones and damage kidneys and heart [8]; MedlinePlus lists confusion, kidney damage and kidney stones [9] | Not more than 100 micrograms (4,000 IU) a day for adults and ages 11 to 17; 50 micrograms (2,000 IU) for ages 1 to 10 [8] |
| Vitamin A | Some research suggests long-term intakes above an average of 1.5 mg (1,500 micrograms) a day may affect the bones [10] | Food and supplements together should not exceed 1.5 mg (1,500 micrograms) a day [10] |
| Vitamin C | More than 1,000 mg a day can cause stomach pain, diarrhoea and flatulence [11] | Under 1,000 mg a day of supplements is unlikely to cause harm [11] |
| Vitamin B6 | 200 mg or more a day can lead to loss of feeling in the arms and legs (peripheral neuropathy) [12] | Not more than 10 mg a day in supplements unless advised by a doctor [12] |
| Calcium | More than 1,500 mg a day could lead to stomach pain and diarrhoea [13] | 1,500 mg or less a day is unlikely to cause harm [13] |
| Iron | High doses (over 20 mg) can cause constipation, nausea, vomiting and stomach pain; very high doses can be fatal, especially for children [7] | 17 mg or less a day of supplements is unlikely to cause harm, unless a doctor advises more [7] |
We tried to read the US NIH Office of Dietary Supplements fact sheets for US Tolerable Upper Intake Levels, but the site blocked our access this session. US levels are therefore not quoted here. See Vitamin toxicity: which vitamins have upper limits, Vitamin D toxicity and Vitamin B6 toxicity.
How people end up taking too much
- Several products with the same ingredient. Check labels for duplicates: Amounts and duplicate ingredients.
- Labels may not match contents. NCCIH says what is on the label may not be what is in the product. [5]
- Large pills. A 2015 study estimated about 23,000 US emergency room visits a year linked to dietary supplements, including older adults with swallowing problems from large vitamin pills and young adults with heart problems from weight-loss or energy products. [5]
Herbs
Proper evidence not found, in the NCCIH, NHS, MedlinePlus and FDA pages we read, for official "upper limits" for herbal products comparable to those for vitamins. What the sources do document is harm from some products at ordinary use, for example liver injury linked to kava. [14] See Liver injury warning signs.
What to do
- Call as above, with the container in hand. See What to tell Poison Help when you call.
- Take the container to the hospital if you go. [6]
- Tell your doctor or pharmacist afterward. Do not change prescribed medicines on your own.
- Report problems with a supplement. FDA lists how to report a problem. [15]
Frequently asked questions
What number do I call if someone took too many vitamins?
In the US, Poison Help at 1-800-222-1222. Call 911 first if the person has collapsed, has a seizure, has trouble breathing or cannot be woken. [1]
Can too much vitamin D be harmful?
Yes. The NHS says too many vitamin D supplements over a long period can cause too much calcium in the body. [8]
Is there a safe upper limit for iron?
The NHS says 17 mg or less a day of iron supplements is unlikely to cause harm, and notes that a doctor may advise more. [7] Iron is especially dangerous for children. [6]
Are herbs safer than vitamins because they are natural?
No. NCCIH says "natural" does not always mean "safe." [5]
What if the product label seems wrong?
NCCIH says label contents and actual contents can differ. [5] Keep the container for the poison specialist and read Quality testing and certifications.
References
- Poison Control (poison.org, US), Need immediate assistance. Read 2026-10-23.
- Poison Control (poison.org, US), Calling poison control. Read 2026-10-23.
- NIMH (US), Suicide Prevention (last reviewed August 2026). Read 2026-10-23.
- MedlinePlus, Poisoning health topic (US NLM). Read 2026-10-23.
- NCCIH (US), Using Dietary Supplements Wisely. Read 2026-10-23.
- MedlinePlus Medical Encyclopedia, Iron overdose (US NLM, reviewed 10/14/2025). Read 2026-10-23.
- NHS (UK), Iron (page last reviewed 3 August 2020). Read 2026-10-23.
- NHS (UK), Vitamin D (page last reviewed 3 August 2020). Read 2026-10-23.
- MedlinePlus Medical Encyclopedia, Vitamin D (US NLM). Read 2026-10-23.
- NHS (UK), Vitamin A (page last reviewed 3 August 2020). Read 2026-10-23.
- NHS (UK), Vitamin C (page last reviewed 3 August 2020). Read 2026-10-23.
- NHS (UK), Vitamin B (B6 section; page last reviewed 3 August 2020). Read 2026-10-23.
- NHS (UK), Calcium (page last reviewed 3 August 2020). Read 2026-10-23.
- NCCIH (US), Kava (last updated April 2025). Read 2026-10-23.
- FDA (US), Information for Consumers on Using Dietary Supplements. Read 2026-10-23.