my neuro had mine checked and my came back at 9 since then i have been taking 2000 i.u per day after i finishes the ones the Dr perscribed and i spend a little more time sitting outside reading.Living in the south makes the possible most of the year in the summer i stayed in the pool almost everyday. I had a recheck and my Vit -D was up to 32 not bad but still take everyday.Hope this is helpful
Gail