What kind of doctor should I go to for hyperparathyroidism?

Whoever Dx'ed you. Hyperparathyroidismal is either primary or secondary. Low 25-oh-vitd levels are one cause for secondary disease, as is renal failure.This must be differentiated. True primary hyperparathyroidism is usually almost always tied to hypercalcemia. Imaging studies may be necessary if an adenoma is suspect. Utrasound is an inexpensive 1st step, followed by a sestemibe scan. If found. Meet your surgeon!
Type of Doctor. If you suspect Hyperparathyroidism, seek out an endocrinologist. If you already have the diagnosis, seek out an experienced head and neck or endocrine surgeon.