What Does Vit D Do in the Body?
There are a number of important jobs that Vit D does:
Measuring Vitamin D status
Generally the next question I get from a lot of people is how do I know if I'm getting enough Vit D. Currently the best way to do this is to measure it in the blood by look at the blood or serum concentration of calcidiol (D2). Wait, didn't I say that the active form is calctriol (D3)? The reason is the 1/2 life of D3 is too short to make it a good indicator as well as it being regulated highly regulated by parathyroid hormone, calcium and phosphate. D3 levels also do not normally decrease significantly until Vit D deficiency is severe.
How Much Vit D is Needed?
If we understand how important Vit D is, the next thing my patients often ask is how much do I need?
As we mentioned above, to know if you personally are getting enough, getting your levels checked is going to be the best option. However, there are general recommendations made by the government which are based on what is called the RDA or Required Daily Allowance. This depends on the average of what works best for a healthy population and maintaining basic requirements for health. In the case of Vit D that's enough to bone health and calcium metabolism, and then in addition the RDA is set based on minimal sun exposure as well. All of this combined, the current daily recommendation for adults and children over 4 years is 400 IU.
If we're trying to raise our levels of Vit D, 400 IU is definitely not going to be enough.
Can I Get Enough from the Sun?
Most people meet at least some of their Vit D requirements from the sun. However, what most people don't realize is that this depends. You need to be outside at the right time of day, and depending on where you live, time of year as well. We need to be exposed to UVB rays at wavelengths of 290-320 nanometers. Other factors that can affect this are: cloud cover, smog, melanin content of your skin (the darker your skin the more difficult it is to 'absorb' enough sun).
Optimal Sun Exposure
The factors previously mentioned and current research that's been done still makes it challenging to know exactly what the right amount of sun exposure is for each person. However, these guidelines are helpful to get some helpful exposure:
- In general, approx 5-30 mins of sun exposure between 10am -3 pm twice a week to arms, face, neck. legs or back without sunscreen [NOTE: if you are monitoring risk for skin cancer, than keep in mind any recommendations from your healthcare provider]
- Spring, Summer and Fall are the optimal times of year, particularly those who live in more northern latitudes
Take Home Message
- Vit D is important for our overall health, and we're still figuring out the full extent of what this entails
- Vit D is present in the diet, and through exposure to the sun we are able to synthesize Vit D
- The drawback is it's tough to determine how much we're getting, so many of us will need to supplement with it at times
- There are safe and unsafe levels of Vit D, and finding out what works best for us personally is likely going to require getting our levels checked periodically.
Have questions about Vitamin D or making sure you're getting what you need to live your best life? Connect with me and we can get a personalized plan together that takes your individual needs into account.
Note: Talk to your Naturopathic Doctor today about getting assessed and treated if needed, and as always talk to your health care provider before beginning any new medication or supplement. This information is not meant to replace the advice/guidance of a medical professional, nor should it be acted upon by individuals unsupervised by the appropriate healthcare provider.
I am a Naturopathic Doctor and Doula providing care in the Kitchener-Waterloo area. I have a passion for helping people with their health issues and improving the birth experience for Moms, and their babies. I also have a life long love affair with soccer, curling, and the alto saxophone.