Do You Know All the Ways that Vitamin D Improves Your Health?

It is apparent that sunlight makes a big difference in how we feel, if you just take note of the overall moods of people on sunny versus cloudy days.  There is a general appreciation for the value of sunlight in our health, but it can be confusing that we've also been taught to fear too much exposure to UVA and UVB rays.  Like everything, balance is key.

Living in a Northern climate puts us at risk of inadequate Vitamin D levels in our bodies, particularly when we are only able to make it ourselves from about April to October, and even then it depends on our exposure to daylight and use of sunscreens.  (And let's be honest, there are a lot of us that drive to and from work in the dark, sit at a desk all day or use SPF 60 to prevent sunburns.)

Interestingly enough, 50% of the world's population is deemed to have insufficient Vitamin D levels, and 1 billion people are deficient in this important hormone. (1) 

So, why is this a big deal?

"..hypovitaminosis D is an independent risk factor for total mortality in the general population."(1)  Meaning that low levels of vitamin D increase your risk of dying.  And given that half of humans don't have optimal levels, this is something to pay attention to.  

Even when we checked Vitamin D status in my patients that supplement this winter, it was common to find deficiency.

Now you know that I don't like bringing things up to scare you, there's more than enough of this going around right now.  I mention the importance of Vitamin D to you because I feel this is something that we can control and modify in order to improve our health.  Feelings of being able to shape your own future  have been shown to increase your ability to handle stress and adapt to change.  You don't need to sit around and wait for illness to find you.


Vitamin D and Its Many Jobs

• Cell regulation
  - by controlling cell growth, insulin production, and blood vessel development, turns genes on/off
  - studies show that those with optimal vitamin D levels are half as likely to be diagnosed with colon cancer as those with low vitamin D
  
  
• Bone health
  - it dramatically increases the absorption calcium and phosphorus (which is why extreme deficiency presents as rickets in children)
  - low levels associated with osteoporosis
  - low vitamin D levels correspond with risk of bone fracture in older individuals
  
  
• Immune 
  - it is an immune system balancer
  - children given Vitamin D in winter have 40% less risk of having Influenza A (4)
  - supplementing shows prevention for TB and acute airway illness (5)
  - has been shown to suppress an overactive immune response and reduce inflammation (6)
  
  
• Cardiovascular 
  - the Framingham Heart Study showed that people with low vitamin D had 60% greater risk of heart disease
  - deficiency of vitamin D is associated with hypertension, possibly through its influence on calcium regulation and the kidneys
  
  
• Depression
  - depressive symptoms improve with optimal vitamin D status
  
  
• Cognition
  - deficiency linked to lowered executive functioning (focus, follow directions, regulate emotions) in older individuals
  
  
• Autoimmune Diseases
  - lower risk of developing type 1 diabetes, multiple sclerosis, Hashimoto's thyroiditis, Grave's disease, IBD, SLE and rheumatoid arthritis when Vitamin D levels are optimal
  
  
• Age-related Macular Degeneration
  - Vitamin D associated with decreased risk
  
  
• Risk of Death
  - Vitamin D3 supplementation reduced risk (7)

Where Do We Get Vitamin D?

1.  Food sources:
    - fatty fish: salmon, mackerel, herring
    - cod liver oil (watch vitamin A dose)
    - egg yolk
    - fortified foods

2.  Sunlight:
Vitamin D actually functions like a hormone, which is different than the roles of other nutrients.  It is made naturally in our bodies when sunlight hits the skin, is hydroxylated by the liver, and then finally by the kidneys to reach its active (useable) form.
    - wearing a hat and sunscreen with SPF 30 or more could reduce Vitamin D production by 95% (2)
    - people of colour require 3-5 times more sunlight exposure than those with lighter skin tones  (3)
    - Northern latitudes are a factor since the angle of the sun's rays and the amount of sun exposure to the skin because of colder temperatures mean that we can only manufacture Vitamin D from about April to October, assuming you get outside at all
    - we make 10,000-25,000 IU of Vitamin D with sunlight exposure (and possibly 100,000 IU on a beach day)
    - lasts twice as long in our blood as supplemented D3

3.  Supplementation
I always prioritize 'natural' ways of obtaining our nutrients or supporting hormone production first, but as you can see, there are reasons that supplementation of Vitamin D is often indicated.
    - D2 is the form that's used in fortified foods, but D3 is the optimal supplemented form of Vitamin D.  In fact, the benefits of Vitamin D on reducing your risk of death were only shown when supplementing with Vitamin D3. (7)

    - It's best to have your levels tested to know where you stand, but the general recommendations for supplementation are: 

•  Infants 400 IU
•  Children 400-1000 IU 
•  Adults 1000-5000 IU

(Higher doses may be suggested temporarily to bring levels into normal range, but should be monitored since Vitamin D can be toxic at high levels.  Vitamin D above 1000IU is considered prescription in Canada.)

     - Other factors that modify dose: amount of sunlight exposure, ability to digest fats (vitamin D is a fat soluble vitamin), BMI over 30, age (the skin isn't as efficient at capturing and producing it, and the liver and kidneys aren't as great at converting it), medications


Vitamin D plays a critical role in our health in ways that we are only just beginning to understand.  I bring it up now because of the overwhelming research to support its value, and the ability for us to control this important predictive health marker, even though not everyone is able to get outside right now.

If you have any questions about how Vitamin D might fit into your own health goals, please ask!  My newsletters are for information, awareness and inspiration purposes only.

Yours in health,
Dr. Christa

1.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356951/
2.  https://www.ncbi.nlm.nih.gov/pubmed/3033008
3.  https://www.ncbi.nlm.nih.gov/pubmed/6119494
4.  https://www.ncbi.nlm.nih.gov/pubmed/20219962/
5.  https://www.ncbi.nlm.nih.gov/pubmed/27009076
6.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5067742/
7.  https://www.ncbi.nlm.nih.gov/pubmed/24414552