Vitamin D deficiency has a lot to do with your climate. It's not realistic to get all of your vitamin D from food no matter what. I'm guessing you live in Seattle or some other place where you forget what the sun looks like sometimes?

Is there any easy way to know if you suffer vitamin D defeciency? I'm in Vancouver, and especially at this time of year you end up inside for pretty much all the daylight hours Monday-Friday.

It's diagnosed through a blood test. As far as I know, you can't really diagnose it accurately in any other way. But in developed countries the rule of thumb on that is:

Do you work outside in the sun? Do you eat a lot of fish? Do you take a vitamin D supplement? If you answered "no" to all of these questions then you probably have a vitamin D deficiency. Vitamin D deficiency is very common.

>The National Health and Nutrition Examination Survey 2005 to 2006 data were analyzed for vitamin D levels in adult participants (N = 4495). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D concentrations ≤20 ng/mL (50 nmol/L). The overall prevalence rate of vitamin D deficiency was 41.6%, with the highest rate seen in blacks (82.1%), followed by Hispanics (69.2%).

https://www.ncbi.nlm.nih.gov/pubmed/21310306

Looks as though I should probably be making a doctor's appointment...

I live in Kansas. I just don't go outside ever. I was always told I was at high risk of melanoma due to my mother having it so I learned to stay indoors. I start burning within 15 minutes of peak sun.

I'm not a doctor, and I'm sure you've gotten good information. But you don't need that much sun to get your vitamin D. 15 minutes is enough for a whole week.

I've found for me personally that vitamin D supplementation helps, but my tendons/muscle attachments are still weak and injury prone unless I get some real sun.

Do you experience symptoms of Vitamin D deficiency?

Yea and I had no idea what it was or that anything could be done. Some could be a coincidence, but it seems pretty likely to be the cause to me. Over the last few months there has been a constant pressure in my lower back that has since gone away. A foggyness in my head has since gone away. Maybe it is some confirmation bias since taking supplements for awhile now, but the change seemed drastic.

Getting less than 5 minutes of sun per month and never eating any foods that contains Vitimin D such as fish for several years might be to blame.

Go to a doctor. A simple blood test for vitamin deficiency takes a few minutes. If you are deficient, you'll receive a prescription for a high dose to help combat the deficiency immediately, and a plan to take the correct maintenance dose over time. If not, you will know there is another root cause behind your symptoms.

This isn't something you should self-medicate. It's tremendously simple for a doctor to confirm your hypothesis.

You dont even have to go to a doctor...there are online testing services that will test vit D w/out a prescription. IO checked mine quarterly for several years.

Supposedly it takes almost 60,000 IU a day for a long period of time to cause harmful levels of calcium in your blood. All supplements recommend 1 dose a day and the largest dosage is 10,000 IU. I see little risk in attempting self medication here. I'll consult my doctor at my next routine checkup, but I'm not worried about this.

From personal experience the head fogginess is a pretty strong indicator of vitamin D deficiency. I didn't even realize I was deficient until I took 5k IU one night and the next morning felt amazing. The Vitamin D deficiency brain fog is almost worse than a hangover or being high IMO.