Thursday, 18 July 2013

Little (miss) sunshine and the heart

These days, I always seem to be thinking about balance in medicine; a balance between risk and benefit, a balanced diet and so on. So as Ireland swelters in unusually hot weather conditions, I’ve found myself wondering about the balance between too little or too much sunlight and the health implications. I’m not alone in this. Over-exposure to sunlight and we need to think about skin cancers, for example. But what about too little? Well, one issue associated with too little sunshine is low vitamin D levels and it is suggested that a large number of the population of Ireland and the UK are currently deficient in said “sunshine” vitamin.

Research about vitamin D seems to be very popular at present and there seems to be an ever increasing body of evidence that vitamin D deficiency is associated with a multitude of illnesses. These range from the role of vitamin D in bone health, cancers, cardiovascular diseases and auto-immune diseases. There is even a vitamin D hypotheses in terms of explaining  the increased prevalence in northern latitude of multiple sclerosis. See Holick MF et al in the Am J Clin Nutr 2004 or Ascherio A. Ann Neurol 2007 for more.

Low vitamin D levels have been linked to increased coronary heart disease risk. However, frequently the findings were in small studies. In the last fortnight research was publish in JAMA regarding the MESA cohort. This was a large study of ethnically diverse patients who were free of clinical heart disease at time of enrollment. Amongst the findings it was noted that low serum levels of 25-hydroxy vitamin D independently predicted raised long-term risk of coronary heart disease events among white participants (as opposed to African American for example). This study was described by a JAMA editorial as being “robust” and it is interesting that outcomes were adjusted for a multitude of CHD risk factors: age, sex, BMI, smoking status, excercise, diabetes status, cholesterol for example, so it appears as if the evidence is getting stronger. See here for more.

Although it would seem that there is an increasing body of evidence linking low vitamin D to increased coronary heart disease, a word of warning. Perhaps it might be best to consider getting your levels checked rather than spending longer in the sun. Skin cancer has been increasing over the past decades. According to the World Health Organisation one in three cancers diagnosed is a skin cancer. Reducing exposure to sunlight’s UV rays really is our own resposibility. See here.

Good advice for the current strong sunlight is don’t forget the Australian mantra regarding adequate clothes, sun-cream and hats, “Slip-Slop-Slap” before heading out into the sun.

For Health Screening Software that gives personalised Vitamin D advice CLICK HERE

No comments:

Post a Comment