Estradiol is an important estrogen steroid hormone in both women and men. It is a typical steroid with core four-ring system (ABCD), composed of 17 carbon atoms. Cutting Ring B produces secosteroids one of which is vitamin D3. 25-hydroxy-cholecalciferol (25-D3); 25-hydroxyvitamin D3 (5ien). Calcitriol is the active form of vitamin D pro-hormone.
Types by function
Cortisol, a glucocorticoid whose functions include immunosuppression
Aldosterone, a mineralocorticoid which helps regulate blood pressure through water and electrolyte balance
Sex steroids
Progesterone, which regulates cyclical changes in the endometrium of the uterus and maintains a pregnancy
Testosterone, which contributes to the development and maintenance of male secondary sex characteristics
Estradiol, which contributes to the development and maintenance of female secondary sex characteristics
Additional classes of steroids include:
Neurosteroids such as DHEA and allopregnanolone
Aminosteroid neuromuscular blocking agents such as pancuronium bromide
As well as the following class of secosteroids (open-ring steroids)
Vitamin D forms such as ergocalciferol, cholecalciferol, and calcitriol
