NUTRITION: Taking a leaf from the book on minerals
LIKE many of us, you may automatically reach for a multivitamin supplement when you are feeling a bit run-down. And you carefully admonish your children to eat their fruit and vegetables so they can get their essential vitamins.
But what about minerals? Do you ever consider these important micronutrients, when you are planning your weekly menu, or reading the label on that nutritional supplement?
Minerals are very different chemically from vitamins, says Dr Celeste Naudé, a dietician and researcher at Stellenbosch University. And they have a different role to play in building your body’s nutritional status.
"Minerals are the inorganic elements that are naturally found in soil and water, and they are often additionally characterised by an exact crystal structure.
"Plants are able to absorb minerals through their root systems, and animals get the minerals they need from what they eat and drink," Naudé says.
In contrast, she says, vitamins are organic compounds, which means that one of the elements in the compound is carbon.
"Organic compounds are produced by living things as a natural result of their function or growth processes, and are not absorbed from the earth by plants, as minerals are," she says.
You need both minerals and vitamins in your diet, but in much smaller quantities than other nutrients such as protein and carbohydrates, hence the term "micronutrients".
And though they’re small, you can’t live without them. They are crucial for maintaining your health, preventing disease, promoting optimal functioning, and advancing physical and intellectual development.
"Humans need minerals for a variety of functions, and their functioning and interactions within the body are complex," says Naudé.
"Generally, they are often used for the formation and construction of the body. One such example is calcium, an essential structural component of bones and teeth. Minerals also play important roles in muscle contractions and the functioning of the nervous system."
Pippa Mullins, a Johannesburg dietician at MME Dietitians, says if you eat a varied diet, you should meet all your mineral requirements. The problem is however, that modern diets don’t always deliver sufficient nutrition.
For example, many people don’t eat enough dairy, meat and chicken to get their iron and calcium requirements, says Mullins.
"Instead they tend to go for convenience foods that are high in carbohydrates and low in protein, and they fill up on chips and bread."
This means that even though your diet should be sufficient to fulfil your mineral needs, you might still be deficient.
On a global level, says Naudé, iodine, iron and zinc deficiencies are the most common mineral deficiencies. Most, but not all, can be detected via a blood test.
This means that you shouldn’t just wake up one morning and decide your iron is low because you’ve been feeling tired. It is preferable to have yourself tested, because simply taking a supplement can actually do as much harm as good.
"As an example, I’ve seen people who’ve decided they’re deficient in magnesium, and take nine times the recommended dose on the supplement bottle," says Mullins.
"All they’ve done is to give themselves bad constipation."
The best way to know for sure that you have a mineral deficiency is to have a blood test, which your doctor can organise. And there’s another reason to see a doctor — your symptoms, despite what you might have read on the internet, could be caused by something else, which your doctor will need to rule out.
Also, if your iron levels are low, for example, it’s not sufficient simply to pop an iron supplement. There may be a more serious underlying condition.
If you do have a deficiency, however, don’t just rush off to the nearest pharmacy or health shop, and pick up a supplement.
"Proceed with caution and get expert advice," says Naudé.
"Nutritional supplementation is only useful when done correctly, and in combination with an adequate and balanced diet."
The trouble is, dietary supplements are not always free of risk. You need to remember that the supplements industry is not regulated by the Medicines Control Council.
There are no guarantees that the products have been thoroughly tested, that the doses are consistent from one batch to the next, or that the product is safe, among other concerns.
"Have a look at the label and the ingredients in the supplement, and think about the claims made there, as well as what the ingredients are," says Naudé.
"If a claim seems too good to be true, it probably is. When in doubt, ask your dietician or doctor."
Supplements on their own are seldom the answer, says Naudé.
You must examine your lifestyle first, she says, and ask yourself whether you could get the same results by eating a healthy diet, getting more sleep or starting to exercise regularly.
"Some mineral supplements have unpleasant and even dangerous side-effects," she says.
Iron is a good example. In most cases, single mineral supplements should only be used to correct a biochemically diagnosed mineral insufficiency or deficiency.
Naudé also says that you should always tell your doctor if you’re taking a supplement, as well as if you experience any side effects with it.
This is especially important when you are taking other medications, as some might interact with supplements, changing their functionality.
Children, teenagers, women who are pregnant or breastfeeding, people who take multiple medications, and those planning to undergo surgery might all be more at risk for the negative effects of supplementation, and will need to be extra cautious.
This is particularly important if you’re facing any surgery, as a number of herbal preparations inhibit platelet function in the body, and interfere with blood clotting and healing.
You might also come across mineral supplements that contain chelated minerals. These are minerals that are bound to another compound, for example, an amino acid.
"There are claims (most often from companies that manufacture or market chelated mineral supplements and products) that the minerals from chelated mineral supplements are used more easily or absorbed better by the body than non-chelated minerals," says Naudé.
"There is no consistent, sound scientific evidence to support this claim.
"In reality, at this point, there is very little scientific information about chelated minerals."
There are specific cases and circumstances in which mineral supplementation as well as mineral-enriched foods can indeed be necessary and helpful, and these can contribute to meeting a specific person’s nutritional needs, says Naudé.
For example, a teenager on a vegan diet may not be getting enough iron for the rapid growth the body is going through, and might need supplementation.
For most of us, a healthy balanced diet can meet our nutrient needs, including our mineral needs.
Supplements of both minerals and vitamins are no replacement for a healthy diet, Naudé says.
"That’s because a good diet, with a variety of foods from all the food groups, is able to supply components that cannot be added to supplements and ‘enriched’ foods at optimal levels in the right combinations, as they occur naturally in foods," says Naudé.
"We should not forget that food has a complex composition that cannot be simulated in supplements. So it’s incorrect to assume that a healthy, balanced diet can be totally replaced by nutritional supplements such as pills, shots or shakes."
If you do have a deficiency, don’t just rush off to the nearest pharmacy or health shop, and pick up a supplement
A good diet is able to supply components that cannot be added to supplements and ‘enriched’ foods
More in this section
- Guptagate report shows manipulation, collusion and illegal blue lights
- SABC presenter Mbuli hailed as patriot and ‘zealous newshound’
- Karabus lawyer says South African nurse behind bars in UAE
- Eskom was ‘on the brink of a power shutdown’
- Iran ‘behind US cyber blitz’
- THICK END OF THE WEDGE: We can already write the NDP off