What is the role of vitamin D in the body?
To say this is one of our most important vitamins would be a colossal understatement. The recent pandemic shone a light on the role of vitamin D in relation to the severity and mortality of SARS-CoV-2 outcomes. While that developing relationship has dominated the airwaves, at the heart of this vitamin is the role it plays in calcium metabolism, immune health and the reproductive tract.
It is thought that vitamin D might have an affinity for the reproductive tract and when there is oxidative stress here, the vitamin can play a protective role and help mitigate the damage. Without it, the body also can't absorb calcium from the gut lining and utilize it to keep our bones strong.
It is those facts that make reports from StatsCan, estimating that 32% of Canadians fall below the recommended levels of vitamin D circulating in the body with 10% being categorized as truly deficient, so distressing. Saying 10% probably doesn't do that stat justice, but what if we said that equated to over 3.7 million of our fellow Canadians?
What is the role of testosterone?
Vitamin D is not the only thing we want to pay attention to when it comes to our vital functions. Testosterone is present in all humans and moderates everything from the distribution of fat and production of red blood cells to the growth of bones and muscles. Testosterone also tends to peak in the summer and fall as the body has spent plenty of time exposed to the sunshine. Perhaps that relationship peaked your interest, leading into our next question.
What is the research on the link between vitamin D and testosterone?
A 2010 study highlighted such a relationship where men were given a daily dose of vitamin D (3,332 IU) for one year. By the end of the trial, they saw increases in all measures of testosterone including free, total and active. The authors noted that further studies were warranted and it happened five years after the first trial.
More recent research suggested there may not be a result at all, but this newer study was less robust. It was far shorter at only 12-weeks long and rather than a daily dose of vitamin D, the participants were given a single mega dose of 20,000 IU once a week. The first study in support of the effect on testosterone also saw individuals with a serum level of under 50 nmol/L included while the latter allowed those up to 75 nmol/L. This suggests to boost testosterone may require vitamin D daily for more than 3 months before you notice significant changes!
Does the sun give us enough vitamin D on a daily basis?
This question is phrased in a way that makes us think, that depends on whether I see the sun each day! There are also countless factors to consider including strength of the sun, hours of sunlight exposure, amount of skin exposed and more. Researchers actually explored just this sort of thought to determine how much time people would need to expose themselves to sunlight to obtain the recommended amount of vitamin D.
They determined that those with darker white skin (skin type III) would need to spend 6 minutes in the noon summer sun at Miami's latitude to reach their daily dose while those with black skin (skin type V) would need to spend 15 minutes in the same light due to differences in melanin.
These levels increase to 15 and 29 minutes respectively when we jump forward to the winter months.
However, when you look at the same experiment in Boston, those same individuals would need to spend an hour and two hours respectively to get their daily dose. The experiment also determined that after 2:00pm, the light is not sufficient enough for even someone with the lightest skin (type I) to meet the recommended levels.
I work during the day! I can't spend an hour or more before two o'clock standing outside in the sun...what are my options?
As we've seen, the trouble with sun exposure is that individuals must weigh the consequences of spending too much time soaking up the rays. This leads them to wonder about safer options, but what exactly are those?
Vitamin D3 supplements are some of the most commonly utilized across Canada, it is no wonder considering our rampant deficiencies relative to some of our more southern neighbours. Most commonly, vitamin D3 is synthesized from animal products such as sheep lanolin, which means it is far from vegan-friendly! Certain non-GMO Vegan D3s are available, sourced from lichen that contain upwards of 1,000 IU per serving.
If you enjoyed this article and want to learn more about vitamin D, check out the Better Together videos on A.Vogel's IGTV and learn how it pairs with other products in the line.
References:
https://pubmed.ncbi.nlm.nih.gov/18844847/
https://pubmed.ncbi.nlm.nih.gov/20363523/
https://pubmed.ncbi.nlm.nih.gov/20363525/
https://pubmed.ncbi.nlm.nih.gov/21154195/
https://pubmed.ncbi.nlm.nih.gov/28938446/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5057046/