Dietary supplements are products containing a "dietary ingredient" intended to supplement the diet. Those ingredients include vitamins, minerals, herbs, amino acids, enzymes, organ tissues or metabolites.
Some dietary supplements are useful, indeed. For example the vitamin folic acid which pregnant women can take to prevent certain birth defects. People insufficient exposure to sunlight can take vitamin D from dietary supplements. Calcium plays an important role in bone strength and that's a proven fact. Older people may have a reduced ability to absorb vitamin B12 from food and in their case crystalline vitamin B12 in supplements can absorbed more easily.
Then again, studies show that there is no strong evidence that supplements are effective. They are of low power, and when they work their effects are short-term and almost all of them are officially described as "Caution and monitor" or "Discourage".
For some dietary supplements, especially those for fighting obesity, there is no proof that they are working. Green tea and ginseng, for example, will not make you lighter. Too little omega-3 acid won't increase obesity - the imbalance between omega-6 and omega-3 will. So, if you take omega-3 in pills, you won't lose weight.
There are two problems with dietary supplements: official regulations and their efficiency. The difference between dietary supplements and drugs is clear: the manufacturer of a dietary supplement must not state that it treats or prevents a certain disease. It also does not have to prove that the supplement is effective, unlike for drugs.
As a result, dietary supplements don't have to be tested before they reach the market and that means that every manufacturer can define its own standard regarding purity and benefits. Since governments in general have lower standards for them, often described just as "it's not harmful", it's easy to market them.
People tend to believe that natural products, as manufacturers often advertise them, are safe. But, "natural" doesn't mean safe, that's just a nice word for a product to sell better. A regulatory agency can withdraw them from the market but only if they are dangerous to the population. That's the practice in many countries and that raises one important question: how do I know that dietary supplements won't harm me?
If you are taking supplements on your own, without consultation with your doctor, dietitian or pharmacist, you can find yourself in a dangerous situation: you may exceed the safe level of some nutrient. Take, for example, magnesium. Magnesium is needed for more than 300 reactions in the body. If you eat green vegetables, beans or nuts, your body will get enough magnesium. Magnesium can be found in tap water too, so there's really no need to take additional pills if you eat a variety of food and drink water.
So, for some ingredients we know that they are useful but here comes the most important question: where those ingredients come from? The answer is very simple: from a healthful diet. Before thinking about a "magic pill" that will solve your health problem, you should take care of your eating habits. If you are eating a variety of foods then your body is getting all necessary minerals, vitamins, and other nutrients. In that case you don't need any supplement.
With all kinds of dietary supplements advertised in different media, how can we know do we need them? Remember that manufacturer's job is to sell them as much as possible and your job is to learn and make an educated decision.
Before taking any dietary supplement talk to your doctor (a supplement may interact with your medicine!), let him examine you and then you'll know for sure do you need something." And remember that healthy lifestyle is the answer for many things: it's better to sleep an hour longer if you are exhausted than to take "pills that restore energy," isn't it? ■