A 48 years old female suffering from severe menorrhagia (DUB) underwent hysterectomy. She wishes to take hormone replacement therapy. Physical examination and breast are normal but X-ray shows osteoporosis. The treatment of choice is:

Osteoporosis in this patient is due to estrogen deficiency. Estrogens are efficacious when administered orally or transdermally. Various types of estrogens (conjugated equine estrogens, estradiol, estrone, esterified estrogens, ethinyl estradiol, and mestranol) reduce bone turnover, prevent bone loss, and induce small increases in bone mass of the spine, hip, and total body. The effects of estrogen are seen in women with natural or surgical menopause and in late postmenopausal women with or without established osteoporosis. Ref: Lindsay R., Cosman F. (2012). Chapter 354. Osteoporosis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.