What is Vitamin D?
Vitamin D is actually a hormone that is synthesized by the skin cells when stimulated by sunlight (UVB rays to be precise, which only account for 5% of the suns’ rays).
Today (July) the sun won’t even rise high enough to produce any vitamin D. And it won’t for all the months of May, June, July and August. Why? Because it’s all about the latitude of the earth. How those rays are going to come in at you. Have a look at this sunshine calendar.
Depending on where you are located, like for us lot in New Zealand, we are really pretty low down, December through to February is peak exposure time, and you need to be out there when you shadow is shorter than you. During the peak months, your body will make enough Vitamin D given that you’re in the sun for 10 minutes if you’re light-skinned and 45 minutes if you are dark-skinned.
This means exposing larger areas of flesh, like your back way more than just your face and hands.
So what do you do during the winter months?
Supplementing with Vitamin D.
There are a few kinds of vitamin D – here we will talk about D2 and D3, but there are other fat-soluble vitamin variants, all of which are sterol (cholesterol-like) substances.
Vitamin D2 (ergocalciferol) is the major synthetic form of provitamin D and Vitamin D3 (cholecalciferol) is made by our own bodies in the skin when exposed to sunlight with UVB. It is also found in animal products and fish oils, notably in fish liver. The traditional knowledge that cod liver oil prevents colds in children lead to scientific research in the 1900s to figure out what in the oil was doing this? (Braun and Cohen, 2015)
Vitamin D has also been traditionally associated with bone health, but now scientists are finding Vitamin D receptors (VDRs) on many and diverse areas of the body like the brain, muscles, prostate, breast and immune cells. (Hossein-nezhad and Holick, 2013) So actually, depending on where these VDRs are found the next step is converting vitamin D – 25-hydroxycholecalciferol – 25(OH)D – inactive, to it’s active form 1,25-dihydroxycholecalciferol – 1,25(OH)2D – calcitriol takes place through different pathways. (Just to be confusing calcitriol can also be called 1-alpha-OHD3, alphacalcidiol, 1,25(OH)2D3 or rocaltrol. (‘Nomenclature of Vitamin D’, 2005)
This is what the Vitamin D pathways look like:
Cholecalciferol (D3) is considered to be the most important dietary form and is identical to the form produced in the body. Ergocalciferol (D2) is produced by fungi and yeasts and is rare in the diet, but is a common supplemental/fortificant form. (Nowson and Margerison, 2002)
Some authors suggest D2 should not be classified as a nutrient, given that it has no natural place in biology. (Vieth, 2006) Whilst both D2 and D3 were previously considered to be equipotent as supplements, recent exploration of this issue points to marked discrepancies in favour of D3.
This is important as for a certain time GP would supplement with D2 though now they are prescribing D3 so double-check. Also, foods that are fortified with D2 like in cereal, for example, are done so with D2. The main issue is that you end up with barely any calcitriol the active form which is the actual substance your body will use for a myriad of processes.
So what does Vitamin D do?
Vitamin D is involved in so many fundamental processes in your body. It regulates calcium and phosphorus, the building blocks of your bones, working out how much to get into your bones or level out back into the blood. It is involved in the mechanisms of cells dividing and growing, super interesting to people involved in cancer research. Vitamin D enhances the immune system’s response to both bacterial and viral agents. (Clancy et al., 2013)
As I mentioned earlier those vitamin D receptors are found on all sorts of cells throughout the body so we know Vitamin D plays a role in blood production, muscle function (vitamin D deficiency has been linked to fibromyalgia (Hossein-nezhad and Holick, 2013) heart function, pancreatic function and brain function.
On a side note, as I mentioned before Vitamin D made in the body comes from cholesterol-type steroid molecules that are in your skin. So you see, cholesterol is really important in your body and if your cholesterol is under 5.1 mmol/L chances are your body is unable to make enough vitamin D on its own. (Pyers, 2016)
How to supplement with Vitamin D?
The best way is to get out into the sun, without sunscreen, though cover your eyes and wear a hat. This is safe as long as you don’t get burnt. This is the most crucial and worrisome part. You just can not get burnt. As soon as you see the tiniest hint of pink colour or redness coming through on your skin get indoors or cover-up. The sun on your skin stimulates more than just the production of Vitamin D it produces beta-endorphins, opioid-like substances that make you feel happy or simply at ease.
The other way is to supplement with vitamin D.
I’ll begin about talking about how not to take too much as I’d like to dissipate this fear from the community.
In 2006 Reinhold Vieth put together a strong critique of the need for there to be a safe upper limit established for Vitamin D intake published in the Journal of Nutrition. (Vieth, 2006) He explains:
Exposure of skin to sunshine can safely provide an adult with vitamin D in an amount equivalent to an oral dose of 250 mcg/d. [This is equal to 10,000 IU per day.] The incremental consumption of 1 mcg/d of vitamin D3 raises serum 25-hydroxyvitamin D [25(OH)D ] by approximately 1 nmol/L (0.4 microg/L). But is reduced once you reach 100 nmol/L. [That would mean once you get past 4000IU is slows down.] Published reports suggest toxicity may occur with 25(OH)D concentrations beyond 500 nmol/L (200 microg/L). [Just to make the point that if it didn’t slow down it the concentration would reach 20,000IU.]
He also says that the message the public has received concerning the guidance level for Vitamin D has not been affected by new knowledge in the field for close to 40 years.
This chart summarising his work shows the toxicity levels of taking Vitamin D. Showing that there was no toxicity in levels below 30,000 International units per day.
So how much vitamin D3 should we be taking?
To be sure, ask your GP to have your Vitamin D blood levels checked. Then you can see how low the levels are and how much you need to top up.
There is a consensus that the Australian and New Zealand populous have very low levels since we live predominantly indoors and that we cover up when we do go outside.
If you came back with a level of 20 ng/mL you’d need to take 5000IU per day to get up to 40ng/mL which is lower end of a normal level in your body. Ideally your vitamin D level should sit at about 48-80ng/mL. (Pyers, 2016) Have a chat with your health practitioner to take the right steps to reach your optimum levels.
Here is a chart showing you how much to take to reach the right levels:
At The Acupuncture Sanctuary we stock Vitamin D supplements in varied potencies to reach healthy levels. We also stock a Green Pasture Cod Liver Oil which is :
Fermented Cod Liver Oil that is made in small batches with extraordinary care. Green Pastures ferment livers from fish that have been exclusively wild caught in the Bering Sea/Aleutian Islands region.
Fermentation is a natural enzymatic and microbial action that releases the oil from the livers. Green Pastures Fermented Cod Liver Oil is a raw, unadulterated, whole food. There are no additives of any kind. It is routinely third-party tested for purity.
This entire product line is certified by the Marine Stewardship Council, which ensures that the cod livers we source have been sustainably wild-caught. (MSC-C-55178) (Fermented Cod Liver Oil – Green Pasture, 2011)
How often do I need to take Vitamin D?
So, this is super important. As we know, Vitamin D is made in the body through two general pathways, either through the liver and kidney – making 25(OH)D which then can survive for approximately 3 weeks. (3-week half-life) and through this pathway is utilised by our bones and in the calcium-phosphorus process. This pathway has been the most researched and is why people are given a huge dose of vitamin D on a monthly basis because doctors know it will hang around for almost a month and not break down. But on the other hand, the less researched – other general pathway is the one where all the other cells with vitamin D receptors in the body are converting the D3 themselves on site. Here the vitamin D only has a half-life of 24 hours. So it is super important to take your supplement or sun exposure everyday to reap the benefits beyond just strengthening your bones. (Do You Take Your Vitamin D Daily? – GrassrootsHealth, 2017)
In a nutshell take 5,000-10,000IU of Vitamin D3 everyday.
Braun, L. and Cohen, M. (2015) Herbs and Natural Supplements, Volume 2 : An Evidence-Based Guide. 4th Editio. Elsevier. Available at: https://login.ezproxy.endeavour.edu.au:2443/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=nlebk&AN=445729&site=eds-live&scope=site (Accessed: 20 July 2019).
Nowson, C. A. and Margerison, C. (2002) ‘Vitamin D intake and vitamin D status of Australians’, Medical Journal of Australia. John Wiley & Sons, Ltd, 177(3), pp. 149–152. doi: 10.5694/J.1326-5377.2002.TB04702.X.
Vieth, R. (2006) ‘Critique of the Considerations for Establishing the Tolerable Upper Intake Level for Vitamin D: Critical Need for Revision Upwards’, The Journal of Nutrition. Narnia, 136(4), pp. 1117–1122. doi: 10.1093/jn/136.4.1117.