Bio-D3 Fem Capsule is used to prevent bone loss in peri and post-menopausal women. Perimenopause is the time around menopause during which ovaries produce less estrogen and stop releasing eggs. Postmenopause is a condition in which women have not had a period for 12 months or longer. Osteoporosis is a bone disease that weakens and thins bones by decreasing bone density, which is common in post-menopausal women.