22 November 2008

Get out in the sun to protect your heart

Supports Chapter 11: Our irrational fear of sunlight

All the 'healthy eating' hype is aimed at preventing heart attacks caused by 'ischaemic heart disease', where the coronary arteries become blocked, either by a build-up of plaque in the artery walls, or by a blood clot. But there are many diseases of the heart – and the one that is responsible for the most deaths is a condition called 'heart failure' or 'sudden cardiac death' (SCD).

We have been told for many years that we should not go out in the sun unless we cover up and/or wear a strong sunscreen. But this measure dramatically reduces the amount of vitamin D our bodies can make from UVB sunlight (our major source of vitamin D). As a consequence, there is now a widespread deficiency of vitamin D in all industrialised countries, particularly those furthest from the equator.

There are also increasing numbers of cases of SCD in those countries.

The classic role of vitamin D for maintaining bone health is well documented and recent reports have linked vitamin D deficiency to various other diseases, including arterial hypertension, diabetes mellitus and cancer which are already covered in Trick and Treat.

A combined German/Austrian study published in October 2008 looked to answer the question of whether vitamin D deficiency also increased the risk of SCD. They found clear evidence that it did, concluding that:
"Low levels of 25(OH)D and 1,25-dihydroxyvitamin D are associated with prevalent myocardial dysfunction, deaths due to heart failure, and SCD."

So, this is yet another reason to get out in the sun – without sunscreen - as often as you can.

Pilz S, et al. Association of Vitamin D Deficiency with Heart Failure and Sudden Cardiac Death in a Large Cross-Sectional Study of Patients Referred for Coronary Angiography. J Clin Endocrinol Metab 2008; 93: 3927-3935.


Anonymous said...

In northern climates it is almost impossible to get enough vitamin D from the sun. Supplements are the only viable solution.

TedHutchinson said...

Working in Mineola,Latitude 40N Aloia and others show 4600iu/daily/vitamin D3 is needed to raise 25(OH)D status above 75nmol/l.
If current satus was above 55nmol/l then only 3800iu/daily was needed while those below 55nmol/l required 5000iu/d.

This link shows average UK adult status through the year. http://tinyurl.com/5h7zby

However, this link http://tinyurl.com/6gj9nz shows to attain the best level for prevention of many chronic conditions a level around 125nmol/l is more likely to be effective.

Consider also that in the USA/Canada vitamin D fortified milk/cereals are available, and living nearer the equator ensures more hours of effective sunshine.

I found 5000iu/daily + regular full body sun exposure only raised my status to 120nmol/l, so I have increased my daily winter supplement to 7000iu/daily. I live in the UK at lat 52N.

Up to 10,000iu/daily of vitamin D3 Cholecalciferol is considered safe.

Anonymous said...

I wonder how my forfathers have been able to survive for this long in the scandinavian area with out suplements and blod measuring devises??

Barry Groves said...

Yes, supplementation is essential in the winter month above about 50 degrees north or south. This is why I am at present writing this in sunny Lanzarote (28N).

The figures and dates I have used in Trick and Treat are based on about 50 degrees (southern England or the US/Canada border).

Thanks for the graphs, Ted. The first one probably reflects the fact that most UK citizens try not to get too much sun. The second one is particularly useful as I believe the RDA for Vit D is based on the amount necessary to prevent rickets. As that graph shows, such a level is woefully inadequate where cancer prevention is concerned.

The good thing about getting vit D from sunlight is that it is impossible to OD as, once it has enough, the body degrades any excess. This doesn't happen when D2 or D3 is obtained from food or from supplements.

Barry Groves said...

Hi Søren

I agree with your sentiment. We all managed to survive because we all ate out traditional, natural diets. These days, health has been hi-jacked for commercial purposes and many of us now eat nutritional garbage.

Anonymous said...

Okay so I should take D suplements in vinter as I live in Denmark? I am blue eyed, red haired, allmost 23 year old male eating Low carb, High fat after your recomendations.
Realy like your books by the way.

Barry Groves said...

Hi Søren

There should be enough UVB in Denmark (Copenhagen) for a useful amount of Vit D production from about the end of March to mid-September, if you go out as often as possible, with as little on as possible, in the middle of the day for, say, half an hour or more.

But for the rest of the year, although our bodies do store vit D, some supplementation is probably needed.

cyber24 said...

I think your latitude calculations are a bit out Barry. The recent Christchurch (44S) study concluded that everyone was vit D deficient.
"Compartmental modelling estimated that a Christchurch person made 1200 IU/day of vitamin D in mid-summer but only 60 IU/day in midwinter. Daily supplements of 1450 or 2600 IU vitamin D3 are predicted to raise the annual minimum mean plasma 25(OH)D to 75 or 100 nmol/L respectively.

Most Christchurch people are vitamin D deficient most of the time and a daily supplement of 2600 IU vitamin D3 would correct this."

Barry Groves said...

Hi cyber24

I'm not surprised at the low levels of vit D in people who observe 'healthy' 'protect yourself from the sun' guidelines.

This just shows that, even in areas where there should be adequate UVB, if you follow such advice, it will be difficult to maintain a healthy level of vit D in your blood.