what type of doctors treat low vitamin D

by Joyce
(McKinney, Texas)

My vitamin D level was 14.2 and my dr. put me on 50,000 mg. vitamin d for 12 weeks. After taking it, my levels did not go up but actually went down a little. He now wants to send me to an endocrinologist or hematologist. Which type of doctor treats low vitamin D levels? Also, is it unusual for for levels not to go up after taking the high dosage of vitamin d for 12 weeks. I've just started taking my second round of the same dosage.