The danger of added vitamins and minerals in sports supplements


Illogical manufacturing

It always puzzles me that the manufacturers of the many sports products that crowd the shelves in pharmacies and sports shops, fall into the trap of adding vitamins and minerals to most of their products.

I fully realise that they are bowing to "give the public what they demand" and that the public will turn to another brand if they don’t keep up with the potentially dangerous practice of adding vitamins, minerals and trace elements to everything from sports drinks to so-called energy bars.

But have these manufacturers never sat down with a calculator and added up how much of each nutrient they provide to the gullible public? If they had a conscience then they would not go in for this type of overkill.

And as is the case for OTC slimming products, no legislative body in South Africa is at present promulgating regulations to halt this flood of excessive vitamins, minerals and trace elements emanating from sports and recreational products.

In similar fashion to the OTC slimming pill market, "anything goes" when it comes to sports supplements.

An example of excess

Too much of a good thing, can only be bad for us. Let’s have a look at a typical individual wanting to lose some weight and build some muscles and add up what quantities of vitamins and minerals that person may ingest on a daily basis:

Our prospective athlete who wants to lose some fat and gain some muscle, will either buy her products from the gym where she works out or visit one of the large pharmacy chains that nowadays dominate the "health and sports product" market.

When she has found the sports section of her local mega-pharmacy she will be confronted by a bewildering array of sports products manufactured locally and abroad, all of which promise instant energy, massive weight loss, bulging muscles, stamina, fat burning, fuelling, and anything else an athlete could dream of.

Urged on by a handsome salesman with bulging muscles and not a gram of fat, our athlete purchases an entire shopping bag of goodies that promise a "body makeover" (not to speak of the financial "makeover" her bank account has just experienced).

Among the many products, there is a packet containing a shake* that can be used to replace meals for the purpose of weight loss, and a packet of a protein mixture* that promises to "build ripped muscles".

Adding up the doses

Ar first glance, the labels of these two products do not convey the idea that using them will expose our athlete to an excess of vitamins and minerals.

a) The shake

The label shows that a serving of shake (2 scoops or 55 g of powder dissolved in a glass of water), will provide between 12% and 86% of the NRVs (Nutrient Reference Values) of the 12 vitamins and 6 minerals it contains, with most of the nutrients at the 35% level. So far so good. However, the instructions on the label of the "makeover" shake state that users should have up to 2 servings per day.

In other words, our athlete will be getting:

2 x 35 or 86 = 70% to 172% of the NRVs for the various vitamins and minerals per day from the shake

b) The protein powder

Once again the label of the protein powder looks relatively harmless. The vitamin, mineral and protein contributions to the NRVs vary between 17% and 157% per 2 scoops or 56 g of powder, with most being about 50%.

But what does the label say about how many servings our athlete should have per day? Interestingly the label encourages her to use “up to 3 servings” a day.

If our athlete is determined to build those ripped muscles and decides to have 3 servings of the protein mix a day, then she will be ingesting the following:

3 x 17 or 157 = 34% to 314% of the NRVs for the various vitamins and minerals per day from the protein mixture.

c) The combination

If we combine the highest percentages of nutrients in maximum servings of both the shake and the protein powder, then our athlete could consume as much as 486% of the NRV of some of these micronutrients. If she also eats a normal meal which contains nutrients and take a vitamin and mineral supplement pill, her intakes could soar off the chart.

Too much is bad for us

“So what! Vitamins and minerals are good for us!”  I hear you say.

“Not true,” say the nutrition experts.

Excessive amounts of vitamins, minerals and trace elements can have the following negative effects:

  • Vitamin A toxicity or hypervitaminosis can cause liver disease, dry scaly skin, hair loss, headaches, nausea, and vomiting. It can also affect the developing foetus during pregnancy.
  • Vitamin D toxicity can lead to calcification of the soft tissues, headache, and nausea.
  • Vitamin E has been implicated in an increase in mortality in patients with heart disease and cancer.
  • Vitamin B1 (thiamine) overdose is linked to convulsions, irregular heartbeat and allergic reactions.
  • Niacin (nicotinic acid) in large doses can cause the release of histamine which results in flushing and may exacerbate asthma and/or peptic ulcers.
  • Vitamin B6 (pyridoxine) may cause pins and needles and loss of sensation in the hands and feet (peripheral neuropathy).
  • Vitamin C (ascorbic acid) can cause upset stomach and diarrhoea, and an increased risk of developing oxalate kidney stones.
  • Excessive calcium intake can lead to hypercalcaemia with pronounced calcium deposits in the soft tissue such as the kidneys.
  • Chromium has been reported to cause skin lesions in athletes taking high doses. It should also be kept in mind that chromium is a heavy metal.

(Mahan et al, 2011)

Until we have legislation to govern the composition of sports products and restrict the excessive amounts of vitamins, minerals and trace elements they contain, please be aware of the risks associated with using large quantities of such products. Instead of achieving glorious health, you could be doing permanent harm to your body.

* The nutrient composition of these two products was obtained from the labels of typical sports supplements purchased in South Africa.


Mahan LK et al, 2011. Krause’s Food and the Nutrition Care Process. 13th Edition. Elsevier Saunders, USA

Any questions? Ask DietDoc

Read more:

Build bigger muscles
Safe weight loss guidelines for athletes
Your guide to legal supplements

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