One third of the world's population needs more sunshine!

New data from a systematic review of almost 200 population-based studies shows that more than a third of populations worldwide may suffer from low levels of vitamin D. Gee, and to think that this particular vitamin is manufactured in the skin by sunlight, it depends on no particular type of food intake and also comes free of charge! 

Yet, researchers from Mannheim Institute of Public Health, Heidelberg University, Germany publishing their findings in the British Journal of Nutrition, stated that of 168,000 people, in 195 studies conducted in 44 countries, 37.3% of the studies reported mean serum vitamin D levels of less than 50nmol/litre. This is a level considered to be inadequate by health authorities. If you’ve missed my vitamin D blog posts in the past, here’s a recap on the recommendations for ensuring vitamin D adequacy.

As a public health measure, universally restoring vitamin D status would not only have a massively beneficial impact on the health status of entire populations, but could be implemented quickly, safely and cheaply. So let the sun shine on - every day. For a continuing appropriate relationship between your skin and the sun...

• Ensure it’s a clear day without pollution
• Minimize UVA while allowing UVB
• 10-15 minutes exposure/day between 10:00 am and 2:00 pm
• Expose 40 percent of skin area
• If this isn’t possible, use oral supplements of D3 to achieve 40-60ng/ml (100-150nMols/L)

RULE OF THUMB: For every 100IU ingested, there is increase of 1ng/ml

PREGNANCY DOSE: 4,000IU/day

BREASTFEEDING DOSE: 6,000IU/day

Vitamin D from the original source

Prof. Edward Gorham from University of California, San Diego Dept. of Family & Preventive Medicine gives us some insights into the epidemic of vitamin D deficiency. He says that insufficient vitamin D affects all intercellular communications with myriad health consequences including cancers, MS, seasonal influenza, diabetes I and II, muscle pains and weakness, impaired wound healing and a number of pregnancy complications such as pre-eclampsia and pre-term birth.

Gorham cites various studies that support the importance of ensuring adequate vitamin D levels at all ages and life stages.

• Onset type I diabetes peaks annually in winter-spring season
• Bone loss study also shows flu symptoms are highest in winter
• Prostate cancer survival is highest in summer
• In USA, 74 percent of the population are below the clinical insufficiency level for vitamin D 
• lower physical activity (i.e. sun exposure) associated with lower 25(OH)D
• lower physical activity associated with higher cancer risk
• women at x 2.25 elevated risk for vitamin D deficiency
• constitutive pigmentation is a risk factor for vitamin D deficiency

Prof. Gorham is an advocate for making the most of the original source of vitamin D, but explains how to use it appropriately. While the sun is the source of UVB photons used to make vitamin D, it’s just a tiny sliver of spectrum that initiates its formation. UVB at 280-319nm and is a long way from the visible light spectrum, it doesn’t penetrate atmosphere easily and perpendicular not oblique rays are required (compare the usefulness of the direct rays from a flashlight to the relatively useless diffuse ones). Pollution and cloud cover are UVB enemies, ditto high latitudes, ditto sunscreens! 

Gorham says that we must re-evaluate our use of sunscreens. They have never been shown to prevent melanoma. However, they irrevocably change the relationship between our skin and the sun - a relationship refined over millenia. Gorham’s prescription for a continuing appropriate relationship between your skin and the sun as follows...

• Minimize UVA while allowing UVB
• 10-15 minutes exposure/day between 10:00 am and 2:00 pm
• Expose 40 percent of skin area
• Ensure it’s a clear day without pollution
• If this isn’t possible, use oral supplements of vitamin D3 to achieve 40-60ng/ml (100-150nMols/L)

RULE OF THUMB: For every 100IU ingested, there is increase of 1ng/ml

PREGNANCY DOSE: 4,000IU/day

BREASTFEEDING DOSE: 6,000IU/day

Vitamin D and the brain

Dr. Thomas Burne, Queensland Brain Institute, University of Queensland agrees that skin cancer is certainly a health problem (particularly in Australia), and that has become a major focus, given that there are very few examples of the real issues of a frank vitamin D deficiency (e.g. rickets). However, he says that the long term effects of vitamin D insufficiency e.g. osteoporosis, immune compromise including cancer, schizophrenia (due to pregnancy deficiency), cardiovascular disease and more are all around us. Vitamin D is essential for the optimal development of the foetal brain.

Messages from the medical profession are still mixed, confused and conflicting, but Burne is in no doubt about the pressing need to reverse the epidemic of vitamin D deficiency. He cites evidence that sunlight stimulates production of Nitric Oxide (NO), reducing blood pressure, saying that this effect alone would far outweigh the issues of skin cancer (which can be cut out or burnt off). 

Cognitive deficits due to vitamin D deficiency are not confined to the infant, but are also apparent in older animals. These are subtle effects but affected rats definitely exhibit a form of attention deficit. They also have muscle weakness, they can’t swim well, can’t float, have multiple other problems. The active form of vitamin D (D3) or 25(OH)D is a cheap, simple way to reverse some of these deficits. 

Find out about supplement dosage during pregnancy and the need for more when you're breastfeeding.

Vitamin D and fertility

Dr. Kelton Tremellan from the University of South Australia has been working with infertile men for years. By-passing their poor sperm quality with IVF techniques such as ICSI was the impetus for Dr. Tremellan to use micronutrients in his infertility practice. He says the same applies to females, they need multiple micronutrients. Recently his work has focused on the importance of vitamin D in improving sperm profiles and fertility in both sexes. 

Dr. Tremellan suggests that only about one quarter to one third of the general population are replete in vitamin D. He says those skin-cancer/melanoma scare-campaigns, urging Australians to “slip, slop, slap” have made their mark!

For optimal male fertility, Tremellan identifies key micronutrients. Antioxidants, which prevent attack by free radicals include vitamins E and C, lycopene and selenium. Vitamin D is another contributing nutrient, with an insufficiency leading to testosterone deficiency and sperm that don’t swim well. These men, with low vitamin D levels may be lethargic and depressed. Sun exposure improves testosterone production. Seems to me that we have a generation of depressed young men, who spend hours in front of a computer screen when they used to be out in the sun riding ride surfboards?

Tremellan asserts that vitamin D therapy can do no harm, it has no side effects and it’s cheap, so why not use it? 

Vitamin D is also important for women. Polycystic ovarian syndrome (PCOS) and insulin resistance (IR) are big contributing factors to female infertility. Both conditions drive testosterone production, which inhibits ovulation. Researchers think the receptor for insulin has a vitamin D response element, making low vitamin D levels linked to low ovulation rates. Poor vitamin D status is also linked to pre-eclampsia and pre-term birth. Maternal vitamin D deficiency is associated with increased rates of asthma, allergies, schizophrenia and other conditions. More to follow on how to improve your vitamin D status and what dose of supplement you need? 

Get a little sun on your skin!

It’s surely not too much to ask in the name of optimal vitamin D status - get out in the sun! I defy anyone to say they don’t feel better when they step outside from their artificially-lit, air-conditioned home or office into a pool of warming sunlight. It’s the ultimate feel-good factor in my book and I’m sure that Nature intended it that way. 

The evidence now points overwhelmingly to the foundation status of vitamin D for optimal bone and immune health (to name just two vital functions) but also points to the widespread deficiency of this key nutrient amongst the general population. The debate as to the best maintenance dose for supplements and the need for ongoing testing to ensure optimal status, leaves me in no doubt about regular doses of sunshine to ensure you’re getting enough. 

For infants, a daily, unprotected sun bath, when the sun is more than 50 degrees above the horizon (but obviously avoiding the hottest part of the day), until the skin has a slight pink tinge, then wash only the smelly parts and all your supplementing issues are solved. Similar recommendation for pregnancy, with additional sun exposure on your nipples excellent preparation for breastfeeding. Same deal re wait for slight pink tone and no washing straight afterwards.

Spend some time in the sun

Consumption of high doses of vitamin D supplements during pregnancy may raise the risk of children developing food allergies after birth, says research.

Vitamin D has been in the news a lot lately - most notably because of the widespread incidence of deficiency that has been noted in Western populations. These are largely a legacy of cancer-council scare-mongering and lifestyles and working environments that are focused mostly indoors rather than out.

Now along with the identified deficiencies comes the debate about supplemental dosage forms and levels and now concern about the potential for Vitamin D during pregnancy to lead to food allergies in the baby - something the supplements would in fact be designed to prevent.

Makes a good case for moderate exposure to sunlight as the best way to prevent deficiency and get the appropriate dose in the appropriate form. So avoid sunburn, limit exposure to the strong midday sun, but ensure some regular, unprotected exposure when the sun is more than 50 degrees above the horizon (it’s at 90 degrees when it’s directly overhead). Vitamin D is manufactured when your skin takes on a very slight pink tinge. 

Depressed? Panic attacks? Try some time in the sun...

Low levels of vitamin D may be associated with an increased risk of depression in mid-life, says a new study from University College London in the UK.

A bit like probiotics, vitamin D is another foundation, health-promoting factor previously ignored or misunderstood and involved in much more than just building bone. The very fact that we call it a vitamin when it is really a hormone is just the beginning...

Now of course, when vitamin D, or rather the widespread deficiency thereof, is better understood we are looking to the best form of supplements and the appropriate dose to counter the deficiencies. These are a legacy of skin-cancer scare campaigns and a society that spends way too much time indoors. Why doesn’t someone simply suggest that the remedy is sun exposure at a time when it will actually promote the production of this vitamin? I’ll admit that’s a challenging recommendation for dark-skinned individuals in higher latitudes but in my part of the world, it’s easily do-able it’s free, guaranteed to work (well if you get the exposure right) and it feels great. I’ve never been a fan of total cover-up from the sun and while I definitely don’t advocate the endless hours on Sydney beaches that marked my early years, I suggest we would all, our kids in particular, benefit from more time in the great outdoors. 

Sarah Berry writing in Sydney Morning Herald April 2012 quotes biochemist and author Lyle MacWilliam who says ‘The current vitamin D recommendations in Australia are seriously out of date.’ So avoid sunburn, limit exposure to the strong midday sun, but ensure some regular, unprotected exposure when the sun is more than 50 degrees above the horizon (it’s at 90 degrees when it’s directly overhead). Vitamin D is manufactured when the skin takes on a very slight pink tinge. There’s debate about how quickly vitamin D, which is oil-soluble, is absorbed from the skin with some experts advocating washing with water only, so use soap on the smelly bits only after your time in the sun.