Few topics in medicine are more controversial than the use of dietary supplements.

The results of large-scale clinical trials are often inconclusive. These tests are designed on the basis of positive results from epidemiological and laboratory data. A common view is that the negative results of clinical trials have shown that a specific supplement is not relevant to the disease and epidemiological studies are biased tests.

Another explanation is that some assays are designed to test the efficacy of the supplementation in the absence of detection of participants baseline nutrients. In other words, it is possible that some people do not respond because they consume adequate amounts of nutrients in question. In fact, some nutrients are lacking appropriate thresholds, ie, researchers do not really know the body needs.

At present, it seems that the food is the best source of variety of nutrients that our body needs. Current guidelines recommend at least five servings of fruits and vegetables every day. Unfortunately, our busy lifestyles often make it difficult to follow these guidelines. So if you have decided to finish, there are some important tips to keep in mind.

First, no more than do. It is a paradox known as lovers of food supplements are generally people who need less supplements. This is because they often eat a balanced diet and lifestyle choices healthy. If you do use supplements, do not take more than the recommended dose of any nutrient through supplements unless specifically recommended by your doctor.

It is particularly important to avoid taking too many vitamins and minerals such as vitamin A, calcium (for men), and iron.

Vitamin A

Vitamin A is a fat soluble vitamin essential for vision, healthy skin, and bone growth. Fat-soluble vitamins are stored in adipose tissue and liver, and blood released when necessary. Because these vitamins are stored for long periods of time, toxic levels can accumulate and cause toxicity. To be on the safe side, look for supplements that contain vitamin A and beta-carotene instead of retinol or retinol versions. Beta-carotene is stored in adipose tissue and is converted to vitamin A as the body physiologically required, thereby avoiding the toxic levels. Also, try not to take more than the recommended daily amount.

Calcium

There is evidence that a high calcium intake increases the risk of prostate cancer and may also increase heart attacks. A large epidemiological study showed that intake of more than 1500 mg of calcium per day may increase the risk of cancer aggressive and lethal prostate cancer. Therefore, men should avoid taking calcium supplements. (Harvard Health Publications, "vitamins and minerals").

Iron

High doses of iron supplements can cause iron overload, which can damage body tissue and increase the risk of infection, heart disease, liver cancer and arthritis.

Also taking high doses of vitamin C increases the body's ability to absorb more iron, which could cause an iron overload.

Always store a supplement containing iron for children to prevent acute poisoning can be fatal.

The general rules

Choose products that are checked or carry ConsumerLab.com Pharmacopeia Dietary Supplement Verification U.S. (USP-DSVP) program brands. These supplements would actually contain the ingredients listed on the label and its real strength. These products are dissolved in 30-45 minutes after ingestion so that nutrients can reach the bloodstream and pass through the body intact. The supplements tested did not contain dangerous levels of contaminants such as heavy metals (such as lead and mercury), bacteria, fungi, toxins or other contaminants. At certain levels of these contaminants can pose serious health risks.

Another good option to consider is that whole food supplements. This is the kind of supplementation that more closely mimic the benefits of a healthy and balanced diet. There are these supplements nutrients in their natural form that allows them to offer a wide range of beneficial effects.

Whatever your choice, you should always consult your doctor or pharmacist before taking any dietary supplement