What is the most appropriate treatment?

A 54-year-old woman was referred for assessment of low bone mineral density. Three months previously, after complaining of bloating and flatulence, she had been found to have coeliac disease and had been started on a gluten-free diet. She had no history of fracture and had not lost height. There was no family history of osteoporosis. Her only medication was omeprazole.

Investigations:

serum corrected calcium2.42 mmol/L (2.20C2.60)

serum alkaline phosphatase122 U/L (45C105)

plasma parathyroid hormone7.9 pmol/L (0.9C5.4)

DXA scansee image

What is the most appropriate treatment?
A . alendronic acid alone
B . alendronic acid, and calcium and vitamin D
C . calcium and vitamin D
D . calcium and vitamin D, and intravenous zoledronic acid
E . strontium ranelate

Answer: C