You can get too much of a good thing when it comes to vitamins and minerals. Image: Pixabay

Health alert: Can you overdose on vitamins and minerals?

Too much of a good thing: When it comes to taking vitamin and mineral supplements, can you actually take too many? The answer is yes!


You can get too much of a good thing when it comes to vitamins and minerals. Image: Pixabay

A little of a good thing does not necessarily mean a lot is better. Taking too many vitamins and minerals can be dangerous and, in some cases, life-threatening. 

Many of the foods we consume are enriched with vitamins and minerals and, if you eat a balanced diet, you will receive all the vitamins and minerals necessary for a healthy body and mind.

However, we also believe that supplementing our diet with additional vitamins and minerals is good practice, and it is here that we need to be careful of giving the body too much. 

You won’t likely overdose on vitamins sourced from food, but care must be exercised when taking vitamin and mineral supplements. Image: Adobe Stock

What is a vitamin overdose?

Vitamin overdose happens when a person ingests too many vitamins and minerals for the body to process. This usually occurs by taking far more than the daily recommendation, for an extended period.

While the body can and does excrete excessive amounts of water-soluble vitamins, such as vitamin C, it can retain fat-soluble vitamins such as vitamin A, which can be toxic. 

It is very important to stick to the recommended daily allowance of vitamins as stated on the packaging or suggested by a health practitioner.

Recommended daily allowances (RDA) are the levels of vitamins and minerals set by the Food and Drug Administration for the general population. You will generally be safe with a multivitamin that covers about 100% of the Daily Value (DV) for all vitamins and minerals. 

It is unlikely that you will exceed your recommended daily allowance (RDA) by obtaining vitamins and minerals from food, but when it comes to supplements you do need to be careful.

What happens when you overdo vitamins and minerals?

Vitamin C

Our bodies don’t produce vitamin C (L-ascorbic acid) naturally, which means we need to get vitamin C from our food or supplements. The vitamin is water-soluble, so it doesn’t get stored in the body. Any excess vitamin C will usually be flushed out with your urine. 

However, taking too much vitamin C can irritate the stomach, leading to gastrointestinal problems such as nausea and diarrhoea. A skin rash may also develop with an overload of vitamin C. 

Recommended Daily Allowance: For adults, the daily recommended dose of vitamin C is between 65mg and 90mg. A tolerable limit of vitamin C is 2000mg – anything above that may cause problems.

Vitamin A

Vitamin A is an antioxidant that is essential for good eyesight, healthy skin and the immune system. Vitamin A can be obtained from meat and seafood (known as preformed vitamin A) and from plant foods (provitamin A). Vitamin A is fat-soluble, and stored in the liver and other body tissues for later use. 

Too much preformed vitamin A obtained from supplements or medicines can lead to headaches, dizziness, nausea, coma and even death, and an excess of preformed vitamin A in pregnant women may cause birth defects.

The first sign of a vitamin A overdose is dry lips, followed by dryness of the nasal mucosa and eyes. 

Recommended Daily Allowance: The recommended daily allowance for vitamin A differs throughout life stages, however, the maximum dose should not exceed 10 000 IU (international units). 


Iron is an essential mineral that plays a part in the formation of red blood cells. The body cannot produce red blood cells, which transport oxygen to the organs, without iron.

Haem iron is obtained from red meat, while non-haem iron is obtained from plant sources. Haem iron is absorbed faster in the body and is a better source of iron. 

Large doses of iron cannot be excreted through urine or faeces and will accumulate in the body. Excess iron is stored in the organs such as the pancreas, liver, and heart and too much iron in the body can lead to nausea, diarrhoea, liver damage, dehydration, and even coma in severe cases.

Recommended Daily Allowance: The recommended daily intake of iron for men aged 19-50 is 8mg and 18mg for women in the same age group. The tolerable limit for adults is 45mg a day.


Zinc is a mineral that is crucial for the proper function of more than 70 enzymes in the body’s organs, tissues and fluids. The mineral isn’t stored in the body for long and it’s important to replenish your zinc levels regularly.

However, zinc poisoning can occur from taking too much supplemental zinc and you may experience symptoms such as nausea, headaches, vomiting and diarrhoea.

Recommended Daily Allowance: The recommended dose of zinc for men over the age of 19 is 11mg and 8mg for women. The tolerable limit is 40mg. 

Important Disclaimer: This article is meant to be informative and general recommendations were used. Every person is unique, and different life stages and medical conditions will influence your need for different vitamins and minerals. Speak to your doctor who will be able to guide you regarding supplements. Also, remember that supplements may interfere with some medications.