Mine was very low 18 months ago. The GP agreed to test as my symptoms of muscle cramps especially when walking, depressed mood and breaking , thinning hair were severe enough. My level was under 20 so I was prescribed 3200iu for ten weeks instead of the usual 400iu. This worked really well and by the end of the ten weeks I felt back to normal. As instructed I then began the 400iu normal supplement but after a few months I stopped for no good reason. Mistake! Feeling the old symptoms coming back I had a private blood test last week at a local pharmacy as I didn't want to resume the 400 dose if mine was low again. Results show that my level is now 35 so that's 'insufficient'. Advice is to take a daily supplement of 1000iu and retest in 3 months
Taz x
