Vitamin D – is it important?
Blue Monday is indeed the stuff of marketing but there’s a more sinister concern that accompanies this time of year if you live in the Northern Hemisphere.
The actual term ‘Blue Monday’ is very recent and yes it’s nothing more than a creation of marketing in an effort mostly to boost holiday bookings.
Nothing wrong with that as such, and a lot of people in the Northern Hemisphere do indeed book their summer holidays in January, but there’s a hidden and less ‘famous’ far more concerning characteristic of winter for much of the population of the northern hemisphere living north of about 40 degrees north and that’s vitamin D deficiency. That’s us in the UK!
As a species in even recent times we would spend much of our time outdoors when sun angles were above 45 degrees from the horizon (typically April-September), but with the rapid rise of the office environment, working from home, cars with UVB filters in their glass and people living further north than they would naturally, much of the population are either low or deficient in vitamin D and this is a problem. (I have personally reviewed over 1000 people’s blood work and >60% were either low or deficient).
The sun angle is important as in the early mornings or evenings the sun angle is low meaning that those early morning sunny walks won’t give you the vitamin D you need as the sun angle is low so much of the UVB is refracted back into the sky. You can check the sun angle where you live here: https://www.timeanddate.com/sun
Have a look for when solar noon is, that’s when you’ll gain the most benefit, however, be mindful of sunburn, particularly if you’re of a light skin tone and you don’t need a lot, 10-20 minutes a day of exposed skin is typically sufficient but there are other factors also. Whilst you won’t acquire Vitamin D, it is notable that Sunlight immeadiately after waking is extremely important for hormonal balance; you can look at the work of Andrew Huberman, PhD for more imformation on this.
As you can see from the image, vitamin D3 is synthesised through the skin and also metabolised in the liver. The primary source is sunlight. Vitamin D is actually a hormone, but the name ‘vitamin’ is used because a classified disease, rickets is attributed to very low levels of vitamin D. Yes, it can be obtained from food but it tends to be most concentrated in organs such as liver which many no longer eat as food. The absolute best source is sunlight.
The concern which has been shown by many health authorities is that populations are low, or deficient in vitamin d3 (25-hydroxycholecalciferol) and this causes health problems beyond the scope of the common thought process of rickets.
These concerns are wide-ranging to the point that the Scientific Advisory Commission on Nutrition released new guidelines for Public Health England advising supplementation of 10micrograms (400iu) per day for EVERYONE over the age of one year. I’d argue this is NOT one size fits all and you NEED to know your numbers.
The official press notice is published here: https://www.gov.uk/government/publications/sacn-vitamin-d-and-health-report
Have fun reading it, I have! In full.
The full report is available here and point 6.242 describes a finding on all-cause mortality and Vitamin D. The report mentions many diseases far beyond skeletal concerns including many cancers and cardiovascular concerns such as high blood pressure, and infection susceptibility appears to be of increased risk – in particular respiratory infections. A sensible systemic review can be found in the British Journal of Medicine, here
In particular, it is noteworthy that a U-shaped relationship exists so exceeding the recommended supplementation isn’t advised unless prescribed by a GP and only then after a deficiency is shown on blood analysis. That is, don’t simply rush out and buy supplements. It can be harmful.
Blue Monday may well be a product of marketing but for those living at higher latitudes, the best and most effective method to increasing serum Vitamin D levels is indeed heading to more southern latitudes and so perhaps it’s not such a bad thing after all.
Oh, and there are also links between low vitamin D and negative mental health consequences – This systematic review describes them here
The point I make is that vitamin D is a vitamin because there is a disease from deficiency, rickets, but it is far far more than just that.
If you are concerned about your Vitamin D levels then it’s sensible to speak to your GP or contact me for a finger prick blood kit that can tell you objectively your levels.
In fact, I strongly encourage you do contact me as your GP will likely do nothing, and I can help you understand the results and put a plan in place. This is cheap and easy.