It is well known that vitamins are essential to us. Unfortunately with so many different vitamins as well as minerals and different intake requirements it can be difficult to understand when supplementation should be considered.
While some vitamins such as Ascorbic acid are dispersed in a large variety of foods, it can be more challenging to acquire enough quantities of calcium, for example, in the standard diet. The problem of vitamin intake is further complicated by the fact that requirements change with age and that some vitamins, particularly those which are fat-soluble (Vitamins A, D, E, K), can become toxic in excessive quantities - a condition more common with vitamin A or D and known as hypervitaminosis.
Still, a large number of people resort to supplementation of vitamins and minerals in an effort to supplement poor dietary intake and/or because of perceived additional benefits from larger intake. However, there is a difference between attempting to fulfill required needs and an attempt to achieve health benefits from "extra supplementation."
Two recent studies have just demonstrated that vitamin supplementation may actually be harmful. The first, a study published in Archives of Internal Medicine, followed 39,000 women aged 55- 59 for 19 years and found that more women who took multivitamins had died over the period than women who took placebos.
The second study, published by the Journal of the American Medical Association, evaluated the impact of vitamin E and selenium on the occurrence of Prostate cancer. This study followed a group of 35,000 men taking either vitamin E, selenium, a combination of both or placebo for seven years. According to the studies authors, those who took Vitamin E alone had a 17% higher risk of developing prostate cancer over the placebo group.
Before jumping to any conclusion it is important to understand these results. First, the design of these studies which require long-term follow-up and compliance may not always be unequivocal. Secondly, there may be other factors in play, and the relationship between vitamin intake and morbidity/ mortality cannot be assumed to be of causative nature.
Despite all of this, these studies have accomplished to shed light on the lack of knowledge of the impact of chronic vitamin supplementation. Thus, with current knowledge chronic vitamin/mineral supplementation without medical indication lacks scientific backing and remains a gamble on your health.
- Study links vitamins to higher death rates in women (CTV News, October 2011)
- Vitamin E may raise risk of prostate cancer (CTV News, October 2011)
- Interested in vitamins? Read another blog about the potential risks of calcium supplements and how they complicate treatments and preventions of osteoporosis.