Can multivitamins be dangerous?

Can multivitamins be dangerous?

By now, you must have seen the craze around multivitamins. The internet is pretty split on whether they are necessary to maintain a healthy lifestyle or if they just create expensive urine. 

Multivitamins are commonly used supplements. Loads of people take them to improve or maintain mental and physical health, protect from nutrient deficiencies or make up a nutrient gap [ usually necessary of the gut isn’t absorbing nutrients from the food we eat].

You can purchase multivitamins without a prescription. However, despite their popularity, these supplements are not risk-free. 

Your body functions on at least 13 vitamins and 16 minerals. A well-balanced diet already has these nutrients packed in. 

Common side effects 

Some side effects of multivitamins occur more than others. These include constipation, diarrhoea, upset stomach and nausea. Gut-related side effects tend to be temporary and disappear as your body becomes familiar with the multivitamin. 

Your healthcare provider can provide you with further assistance if your symptoms persist. 

Rare side effects

Rarer side effects of multivitamins include headaches, nosebleeds, insomnia and gout. These effects infrequently occur if the nutrients in your multivitamin do not exceed the recommended daily limit.

Multivitamins combined with other supplements or eating a large number of fortified foods exceed your daily limit. This may increase your risk of side effects. 

Specific multivitamins have caused people some severe allergic reactions. The reactions include hives, difficulty breathing, or swelling of your tongue, lips or throat. If any of these reactions happen to you, seek immediate medical assistance.

Nutrients to watch out for

Multivitamins have three categories of nutrients:

Water-soluble vitamins

These vitamins dissolve in water and don’t mainly accumulate in your body. If taken excessively, water-soluble vitamins may cause severe side effects. 

If your intake of Vitamin C is three times larger than the upper limit, it may cause cramps, diarrhoea, nausea, vomiting or migraines. The same applies to ingestion three times above the upper limit of vitamin B3. The overdose can cause stomach pain, high blood pressure, vision problems and liver damage. 

Fat-soluble vitamins

They dissolve in fat and accumulate in the body. By exceeding the dosage, you can reach toxic levels. 

If ingestion is too much, vitamin A may lead to headaches, liver damage, weaker bones and congenital disabilities. Smokers and former smokers should avoid high amounts of vitamin A or beta carotene as it increases the risk of lung cancer. 


Minerals are inorganic elements. In excess, these can cause harmful effects.

A high intake of certain minerals, such as iron, copper, magnesium, and zinc, can upset the stomach, constipation, diarrhoea, nausea, vomiting, stomach pain, and headaches. Excess iron intake is also harmful to your liver.

Too much iodine in multivitamins may cause thyroid problems, and excessive selenium can lead to garlic-like breath, hair loss, brittle nails or a metallic taste in your mouth. 

A balanced approach

Overall, multivitamins are helpful if you cannot reach your daily nutrient needs with your diet alone. It cannot replace a balanced diet. Multivitamins taken in high amounts may lead to severe side effects. 

For example, arsenic or lead are harmful compounds that can contaminate multivitamins. When taken in large amounts or over a lengthy timeline, various health problems may occur, including physical, muscular, neurological difficulties and congenital disabilities.

If you are going to take multivitamins, minimise your risk by taking them when you need them. 

Not recommended for children

Side effects in children and adults are similar. However, children have a lower tolerance level, so they can only receive lower doses than adults before it starts to cause symptoms.

Kids who take multivitamins regularly may have a higher risk of nutrient overdoses. Some kids have died.

Companies market many multivitamins specifically for infants and children. But, a recent study suggests that up to 65% contain nutrient levels above the safe upper limits (UL) for children.

Experts report that children who consume multivitamins have a higher risk of exceeding the UL, particularly for vitamin A, folic acid, and zinc.

Giving your baby an iron-containing multivitamin when they don’t need it may also cause them to overdose on iron. Scientists assume this to be a lead cause of poisoning in children six years old and under.

To reduce the risk of side effects or toxic overdoses, make sure to consult your healthcare provider before giving your child a multivitamin.

The Medical Society

The Medical Society covers you and your family for whatever unforeseen illnesses may come your way, offering affordable health care for adults. Adult members are covered receive cover for an array of Primary health care treatment benefits.  

From only R89 per month, members get unlimited nurse room visits and dietary advice from professionals.

Adults also receive chronic illness monitoring, advice, and prevention for high blood pressure and diabetes conditions. 

Treatment for minor medical conditions such as sprains, cuts, bruises and burns is also available. 


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