I believe that you need to be at 40ng/mol to be considered getting sufficient vitamin d. So in my opinion you are deficient - however I am not a doctor so you should probably ask your doctor before you start taking supplements.
Yes, you are low. I was too and have been taking about 5000 IUs per day for the last 4-5 months. I may be 'healthier', who knows. But it has had absolutely zero effect on my skin.
