Nutritional supplements are only necessary if your diet is imperfect, which means some nutrients are lacking or deficient.
Nutrients are chemicals/substances that are required for metabolism, various functions, and growth.
If the deficiency is significant, especially if such a diet is prolonged, then some aspects of health will be affected.
The problem in poor countries is outright deficiencies of many nutrients due to malnutrition. In rich, developed countries, deficiency diseases are not expected to occur because malnutrition is not a problem.
However, even rich people may not have healthy diets, and deficiency diseases still occur because of diet-choices rather than poverty.
For example, people who consume fat and calorie-rich meals may end up deficient in many essential nutrients.
The best solution is to improve the diet so that it will provide all (or at least most) of the important nutrients so that good health can be maintained. But that requires discipline, something most of us lack when it comes to eating (and exercising).
This is where supplements come in.
Since most of us do not have perfect diets, we will need some supplementation, but the challenge is to know what is lacking, especially if the deficiency symptoms are not obvious.
Do we need supplements?
While gross deficiency gives rise to recognisable symptoms (e.g. scurvy due to vitamin C deficiency; rickets due to vitamin D deficiency in children), we do not want to wait until such deficiencies become obvious and dangerous before we act.
For example, large-scale studies have shown that many Europeans and North Americans who live in the northern part of the continents are deficient in vitamin D because of the lack of sun exposure that predisposes them to osteoporosis (especially in postmenopausal women) and many other health problems now associated with vitamin D deficiency.
The Archives of Internal Medicine reported that up to 77 per cent of Americans are vitamin D deficient.
Dark-skinned people (Indians immigrants and African-Americans) living in the northern regions of these continents suffer most because their dark skin (melanin-rich) reduces vitamin D production by up to 90 per cent.
Historically, dark-skinned people live in areas where there is much sunlight and the melanin protects against damage due to over-exposure to the harmful rays from the sun.
We are fortunate here that we get more sunlight. But our modern lifestyles (spending more time indoors at work, watching TV, and being busy with the Internet - Malaysians are the Facebook champions of the world) also limit our exposure to sunlight, and many of us may actually be vitamin D deficient as well.
The vitamin D deficiency problem is just one example of possibly many more nutrient deficiencies we may have without knowing.
In this case, the only sure way to know is by doing a blood test, which is expensive here and therefore not practical as a routine test yet.
The controversy, however, is more on whether people who do not have deficiency diseases could benefit from supplementation. That is, above the minimum required to prevent deficiency problems, is it beneficial to have higher intakes and higher blood/tissue levels of the nutrients?
Dangers of overdosing and toxicity
Besides the possible benefits, are there also potential dangers of overdosing and toxicity?
It is worthy to note that most of the dietary guidelines given for vitamin and mineral daily intakes refer to the recommended amounts to prevent deficiency, and not necessarily to promote optimum health.
While the experts agree how much is required to prevent deficiency disease, they are still debating about how much is desirable for optimum health.
For example, vitamin D has been found to have several important functions beyond its role in bone health.
It is involved in the regulation of about 2,000 of our genes; cellular proliferation and death; insulin production; the immune system; reducing inflammation; promoting heart health; and may influence outcomes of several types of cancer.
Added on to the fact that most are unaware of the problems vitamin D deficiency may cause, many experts have suggested that the US authorities increase the recommended daily vitamin D intake from 200 IU to 1000 IU.
Yet, a recent study by Johns Hopkins University School of Medicine showed that too much vitamin D can be harmful to the heart.
So we need to be cautious and get expert advice before taking high-dose supplements.
While there are many claims that various nutritional supplements improve the health of many people, we should be guided by scientifically validated data to base our conclusions, and for health practitioners to advise their clients.
Fortunately, there are now more such supplements that have undergone scientific studies. These supplements can make valid claims about their benefits, just as drugs are allowed to make claims based on research done.
However, those who are not in the scientific field should be aware that "scientific studies" could mean many things.
It could mean studies in the lab, studies on animals, and studies in humans. The studies could also be small, non-randomised, and non-controlled (without an untreated group or group given placebo-treatment as control).
However, because large gold-standard studies are expensive, these are not usually available for nutritional supplements.
Much of the information about the benefits of the nutrients we have also come from observational studies, such as surveys.
With these limitations, it is still important that we base our supplementation decisions on the available scientific knowledge.
Foremost is the safety factor. It is alright to take a supplement for an expected but yet unproven benefit if it is safe (though you waste money if it turns out to be not as beneficial as claimed).
It is a double whammy if the supplement turns out to be useless as well as harmful. Thus it is important that you seek expert advice on your supplementation programme.
What sort of supplements should I consider?
Each of us will have a different requirement depending on our diet, and current health status.
In my opinion, the best supplements are those that are made of whole foods, ie. the nutrients from entire fruits, veggies or other foods are present.
Our body is meant to get the nutrients from food. The nutrients come in natural form, and in composition and proportions best suited for our body. Most nutrients also work in synergy with other nutrients which are usually present in the right amounts in food.
In some cases, the co-factors are crucial to the optimum functioning of the intended nutrient.
For example, studies have shown that tocotrienols ("super" vitamin E) can be made a thousand times more effective in the presence of certain citrus bioflavonoids.
Therefore, the best way to get your nutrients is from the food that you eat, provided you choose a nutrient-dense diet rich in fruits and veggies, whole grains, beans, legumes, some nuts, and deep-sea fish (for non-vegetarians) to provide the widest possible range of nutrients.
However, heating, cooking and some forms of processing may destroy many of the nutrients and make the original, natural composition become much less beneficial.
Since most of us have imperfect diets, and many indulge in really unhealthy diets, then the best way to compensate for this is to take whole-food supplements.
This will help ensure that the nutrients that are missing in the diet are obtained the second-best way - by getting the same nutrients concentrated in a capsule.
Whole-food supplements provide a wide range of nutrients that are present in the foods that make their ingredients.
However, if you require supplementation of a single or only several nutrients, you still should choose the supplements that are extracted from natural sources, as opposed to synthetic or chemically-manufactured ones.
In most cases, the synthetic versions still differ in their effectiveness in the body compared to the natural ones due to subtle differences in the molecular structure and behaviour, even though the chemical name may be the same.
Only in the absence of the natural-extract form do I recommend synthetic supplements.
You will only require these single-nutrient supplements for special reasons, or if your diet obviously lacks these particular nutrients.
If patients ask me for a supplementation programme, I need to know their diet, lifestyle, current health and medication they are taking.
I also do a thorough hormone assessment and optimisation, because they will not get the most out of their supplements if their hormones are also not corrected (e.g. vitamin D and calcium).
What dosage is appropriate for me?
Like drugs, you also need the right doses of supplements to achieve the desired results.
Sometimes, people try to save money and under-dose, and end up not benefiting at all.
At the other end, it does not always mean that more is better, and some supplements can be harmful if too much is taken.
For example, the controversy over the recommended dose of vitamin C supplement.
This dosage controversy exists for many nutrients (see vitamin D above) simply because research is severely lacking, compared to the research done on drugs.
Dr Amir Farid Isahak is a medical specialist who practises holistic, aesthetic and anti-ageing medicine. He is a qigong master and founder of SuperQigong. For further information, e-mail firstname.lastname@example.org. The views expressed are those of the writer and readers are advised to always consult expert advice before undertaking any changes to their lifestyles. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.