Supplements – what you need to know

Despite the appeal of supplements, we should not rely heavily on them to meet our needs. Epidemiological research has shown that supplements do not provide all the benefits that foods do. Studies show that people who eat more fruits and vegetables have a lower incidence of a host of chronic diseases. These same benefits are not duplicated by taking supplements of nutrients found in these foods.

It is important to remember that nutritional supplements should be viewed as medicines that have both subtherapeutic and toxic doses, as well as the potential to induce adverse reactions and interactions.

What supplements will not do:
  • Supplements can never compensate for a poor diet: they cannot counteract a high intake of saturated fat, nor can they replace every nutrient found in food groups that do not form part of your diet.
  • Supplements cannot compensate for habits known to contribute to ill health, such as smoking or lack of exercise.
  • Although some of the benefits ascribed to supplements are unproved but plausible, other claims are far-fetched, particularly those made for some weight-loss preparations. It is questionable whether any such preparation can make you shed kilos without  making the right food choices and taking regular exercise at the same time. Products that claim to ‘burn fat’ won’t burn enough on their own for significant weight loss.
  • No supplements are known to have the capacity to cure serious diseases such as cancer, heart disease, diabetes or HIV/AIDS. However, the right supplement may help to improve a chronic condition and to relieve symptoms such as pain and inflammation.
Buying supplements: preparation and forms
Natural versus Synthetic

It is often asked whether natural or synthetic forms of vitamins are the same and whether one is superior or safer to the other. At this stage, very little research has been conducted to compare natural and synthetic forms of vitamins; however, some investigation into vitamin E has been undertaken.

The biological activity of vitamin E is based on the ‘fetal-resorption-gestation’ method in rats. Using this test, the minimum amount of vitamin E required to sustain fetal growth in pregnant rats is determined. In the case of d-alpha tocopherol, which is considered the natural form of vitamin E, the highest activity is observed and therefore valued at 100%; whereas the biological activity of other vitamin E isomers has been estimated to be as low as 21%. Studies in humans have indicated that natural vitamin E has roughly twice the bioavailability of synthetic vitamin E; however, whether this also means greater efficacy has yet to be clarified.

It has also been speculated that natural beta-carotene used in supplements, which is derived from algae and contains a mixture of carotenoids, may be safer and possibly more effective than synthetic beta-carotene.

Tablets & Capsules

Tablets are likely to contain more, usually inert, additives known as excipients. These compounds bind, preserve or give bulk to the supplement, and some can help tablets to break down more quickly in the stomach. Capsules tend to have fewer additives than tablets, and there is evidence that they dissolve more readily, although this does not necessarily mean that they are absorbed better by the body.

Chewable tablets

Such supplements are usually flavoured, and can be useful if you struggle to swallow pills. They are often high in sugar or artificial sweeteners though.

Sublingual liquids and tablets

These supplements are formulated to dissolve sublingually (under the tongue), providing quick absorption into the blood stream without interference from stomach acid or digestive enzymes.

Chelated minerals

Minerals in supplements are chelated, or bonded, to another substance. This may be an inorganic mineral, an organic substance or an amino acid. The substance to which a mineral is chelated dictates how well it is absorbed. Inorganic chelates, such as oxides, sulphates, phosphates, chlorides and carbonates, tend to be cheaper than organic chelates but less well absorbed. Organic chelates, including ascorbates, citrates, succinates and malates, are better absorbed.


There are hundreds of probiotic preparations available on supermarket and pharmacy shelves. However, when tested, many of them do not contain the amount of live organisms that they claim to. There are many probiotic preparations that can be used to target very specific gastrointestinal complaints – for example, one that would be used for small intestinal bacterial overgrowth would differ from one used to remedy bloating in the lower gastrointestinal tract. Get advice from a qualified health professional before spending your money on expensive preparations that may provide no further benefit than eating bio-live yoghurt.