Your doctor can run a simple blood test.

The simple blood test any doctor can do it I am D deficient I understand it can be hereditary

I have a vitamin B12 deficiency and on my last testing I found out that I also have vitamin D deficiency too
This was found in my routine blood test done at my doctors xx

Blood test
Should be part of a general testing that's done annually

Your gp can do it--just a blood test