Vitamins & Minerals
Exercise & B-vitamins Vitamin D & diabetes Vitamin E & lung cancer
Exercise and B-vitamin requirements
The B-vitamins play a variety of essential roles in the body which include supporting metabolism, aiding cell synthesis & repair, enhancing immune function and maintaining healthy skin & muscles.
Whether exercise increases a person's requirement for B-vitamins has been debated for quite some time now. The theory of active people needing more of these micro-nutrients stems from the fact that B-vitamin deficiency may decrease exercise performance at high intensity. One review looked at the available research to try to draw a firm conclusion on this subject (Manore & Woolf (2006) B-Vitamins and Exercise: Does Exercise Alter Requirements? International Journal of Sports Nutrition and Exercise Metabolism, 2006, 15(5), 453-484).
The researchers focused on the role of B-vitamins in energy metabolism and cell regeneration and found that exercise may increase a person's requirements for riboflavin and vitamin B-6 but more study was required to assess the needs for folate and B12. One of the most significant findings of this review was the lack of studies examining the effects of B-vitamin deficiencies on performance.
Vitamin D reduces diabetes risk
Type I diabetes is becoming more common. In fact, it is estimated that the number of new cases will rise by 40% between 2000 and 2010. Preventing this condition is, therefore, becoming more of a pressing issue for researchers and clinicians.
New research suggests that supplementing young children's diets with Vitamin D may reduce their risk of developing type I diabetes later in life (Zipitis & Akobeng (2008) Vitamin D Supplementation in Early Childhood and Risk of Type I Diabetes: a Systematic Review & Meta-analysis. Archives of Disease in Childhood, 2008).
The research was carried out at St Mary's Hospital for Women and Children in Manchester and showed that children who took Vitamin D supplements were ~30% less likely to develop Type I diabetes as adults. In addition, the results showed that the effect was dose-dependent - those who took higher doses, more regularly were at least risk.
In the past, research has shown that people with type I diabetes have had lower concentrations of Vitamin D. Vitamin D is manufactured in the body through exposure to sunlight so it makes sense that the condition is more common in countries where exposure to sunlight is low.
Vitamin D has also been labelled as important for reducing diabetes risk as certain cells in the pancreas (the place where insulin is produced) have receptors for the active form of this vitamin.
However, no concrete link has been made between vitamin D supplementation and reduced diabetes risk and much more research is needed to formalise this link before it is recommended as a preventative measure.
The Government recommends that children are supplemented with Vitamin D until they are two years old. The Chief Medical Officer (CMO) has suggested that supplements are given for the first 5 years of life though.
Remember, as with all Vitamins and Minerals, excess Vitamin D intake can be toxic - therefore it is recommended that you consult your GP or pharmacist before giving supplements to your children or taking one yourself. Long term intakes of Vitamin D above the recommended values - up to 25 micrograms for children up to 1 year old, up to 50 micorgrams for those over 12 months old - may increase the risk of adverse health effects.
High does Vitamin E increases lung cancer risk
American researchers monitored over 77,000 adults to investigate the long-term use of multivitamins, vitamin C, vitamin E and folate on the risk of developing lung cancer (Slatore et al (2008) Long-Term Use of Supplemental Multivitamins, Vitamin C, Vitamin E and Folate Does Not Reduce the Risk of Lung Cancer. American Journal of Respiratory and Critical Care Medicine, 177, 524-530, 2008).
The team found that none of these supplements reduced lung cancer risk - in fact, vitamin E was associated with a small increase in risk.
The results of the study suggested that taking 400mg of Vitamin E every day for 10 years increases the risk of lung cancer by 28% whereas taking 100mg increases risk by 7%.
Cancer Research UK estimate lifetime risk of developing lung cancer as 8% for men and 4% for women. Increasing this risk by 28% results in a lifetime risk of 10% for men and 5% for women.
However, lung cancer is more strongly correlated with smoking, a family history of disease and increasing age.
This study further highlights the fact that taking high doses of vitamins and minerals when they are not needed, can increase the risk of certain conditions rather than decrease it. Too many people consider supplements as the answer to a poor diet and unhealthy lifestyle.
If you are considering taking a vitamin or mineral supplement, you should always consult your GP or pharmacist to ensure that it is suitable for you.