Why You Should Be Supplementing With Vitamin D3
Fall is upon us here in New England right now. The days are getting shorter and darker, the temps are cooling down and all outdoor “Covid-friendly” spaces will soon be too cold for socially distanced events and gatherings. It’s the time of year when we all start congregating inside and seeing high incidences of usual “colds, sniffles, the flu and stomach bugs” kicking up. I don’t mean to be a killjoy over here, but you all know what I’m talking about. The change of seasons, declining temperatures and lack of sun are some variables that can wreak havoc on our immune systems. Now more than ever, we should all be laser focused on fortifying and strengthening our immune systems as Mother Nature (and the world) throws some curveballs at us.
WHAT IS VITAMIN D?
Vitamin D aka “the sunshine vitamin” is an extremely important vitamin for your skin and beauty, bones and strength, and most importantly overall health and immunity (this is what we are here for.) However, an estimated one-billion people worldwide have a vitamin-D deficiency (VDD.) It’s important to know what vitamin D is, how to discern if you’re are lacking this vital vitamin, and what you can do about it.
Vitamin D is a fat soluble vitamin, meaning it can travel into your blood circulation and be stored in your body’s tissues. It’s the only vitamin that can be produced in the body on its own, making it more of a hormone than a vitamin. It does so when your skin has direct sun exposure (particularly with the UVB rays from the sun) to produce D3. Though vitamin D exists in 2 forms, humans cannot make vitamin D2.
Vitamin D can also be found in some food sources: Fish is an especially helpful supply, particularly wild, low-mercury salmon and mackerel (source of D3.) In addition, mushrooms grown with exposure to UV light (versus the many mushrooms grown in the dark which would not provide vitamin D) are also a good food source (vitamin D2.) Last of course you can get Vitamin D2 and D3 from supplementation.
Once your body takes in vitamin D, chemical processes in your liver allows it to absorb into your blood. Your blood then directs it through your tissues and into your kidneys. There, it turns into activated vitamin D (also known as calcitriol). In this activated form, it now supports the calcium supply and absorption by your blood, bones, and gut (where the majority of your immune system lives.) It helps the cells in your body to grow and function properly. Here’s a graphic of how vitamin D works in the body from any of the three sources:
Vitamin D synthesis from three different sources.
HOW TO KNOW IF YOU ARE ‘D’EFICIENT
As vitamin D plays a crucial role in your body, it’s important to ensure your body gets enough of it. However, like I said earlier, research has shown that a large percentage of people don’t...over 1 billion of us and counting!
Your geographic region plays a large role on your ability to get vitamin D3 from sunshine (which is the ideal way to get your D.) The Harvard Health blog states unfortunate findings. Outside of summer, there’s little to no chance of getting vitamin D3 from the sun for those at latitudes above 37 degrees north (a high percentage of the US) or 37 degrees south of the equator. Yes Granite Staters, I’m talking to you!
Vitamin D3 availability from geographic location.
But it’s not just those below the 37th degree that can be vitamin-D deficient. Even in sunshine locales like Florida, deficiency is prevalent due to the extensive use of—and need for—sunscreen. Also, anyone who doesn’t spend sufficient time in sunlight can have a vitamin-D deficiency. The recommended time varies due to a variety of factors. For instance, those with darker skin have a greater chance of being deficient because skin pigments act as natural sun protection.
Additional populations at risk for vitamin D deficiency (VDD) are: breastfed infants (vitamin D requirements can’t be met by breast milk alone), the elderly, being overweight or obese, having undergone gastric by pass surgery, having any kind of fat malabsorption syndrome (ex. celiac sprue,) staying home bound/inside too much (*ugh*) and those who always go outside wearing SPF that’s 30 or higher (without ever having any kind of sun exposure without sunscreen.)
When sun exposure is simply not an option, natural food sources, vitamin D-fortified foods, and supplementation are a must.
SIGNS YOU MAY HAVE A VITAMIN-D DEFICIENCY
Because of the prevalence of vitamin-D deficiency and the role it plays in your body, it’s important to know the signs. If you think you might be missing out on vitamin D, connect with your doctor about getting tested for the next steps, it’s a simple blood test to see where you’re at. My family and I all have our levels checked and managed by our naturopathic doctor (ND)...love her! Serum 25(OH)D is considered the most accurate marker for vitamin D status.
Here are five common signs that your body might have a vitamin-D deficiency: weak bones and muscles, depression - particularly Seasonal Affective Disorder (SAD is a mood disorder characterized by depression that usually occurs during winter - it’s related to the decrease in sunlight your body gets.) Poor skiing health, acne or eczema (especially in Winter months) as well as frequent colds and infections/weakened immunity.
Vitamin D plays a role in your body’s response to infectious diseases like the flu, common cold, or tuberculosis. Calcitriol is known to boost the immune cell production of microbe-fighting proteins. There are vitamin D metabolizing enzymes and vitamin D receptors present in many cell types including various immune cells such as: antigen-presenting-cells, T cells, B cells, and monocytes.
Low levels of vitamin D have also been associated with frequent infections. Back in 2009, the National Institute of Health (NIH) warned that low vitamin D levels are associated with frequent colds and influenza.. Since the NIH announcement, there have been many studies to determine the best regimen of vitamin D supplementation and to better understand this association.
In 2017, a large analyses of prospective clinical trials showed that taking vitamin D3 reduces the odds of developing a respiratory infection by approximately 42% in people with low baseline levels of 25-hydroxyvitamin D; below 25 ng/mL. The analysis suggests that taking vitamin D daily or weekly was more effective than larger doses taken in single or monthly boluses.
SUPPLEMENTATION
In cases when it is not possible to get vitamin D through sun exposure, take supplements. Hopefully I’ve made enough of a case for you to be doing this, like now. Again, Vitamin-D supplements use two forms: D2 (ergocalciferol) and D3 (cholecalciferol). The D3 is the same chemically as produced in the body and is thus the preferred form.
Vitamin D is measured in IU’s, the International Unit usually used to measure fat-soluble vitamins including A, D, and E. The recommended dose of vitamin D is up for debate among medical professionals and this is outside my scope of practice. While the respected medical community continues to evaluate “normal” levels of vitamin D in the blood, this raises the issue: is normal the same thing as optimal? Not necessarily.
This time of year, be sure to get your Vitamin D levels and be sure to get on a good quality product (that is something I can help you with.) Be sure to have you and your Doctor shoot for optimal levels as far as dosing is concerned.
Be and stay well everyone!
1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356951/
2 https://www.health.harvard.edu/blog/vitamin-d-testing-recommended-people-201411267547
3 National Institutes of Health. Low Vitamin D Levels Associated with Colds and Flu. NIH website. https://www.nih.gov/news-events/nih-research-matters/low-vitamin-d-levels-associated-colds-flu. Published March 9, 2009. Accessed September 14, 2019
4 Martineau AR, Jolliffe DA, Hooper RL, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. 2017;356:i6583.