This edited volume contains six chapters that each describe recent advancements in medicine and biology. Chapter One summarizes recent discoveries regarding the immunomodulatory effects of vitamin D3 on human health with an emphasis on the interplay of transcription factors and reviews the most recent recommendations based on new clinical evidence for vitamin D3 dosages for the prevention and treatment of COVID-19. Chapter Two focuses on idiopathic membranous nephropathy, the most common cause of nephrotic syndrome in adults who do not suffer from diabetes mellitus. Chapter Three details the emerging worldwide prevalence of myopathies, their evolving diagnostic parameters, and the newer therapeutic modalities. Chapter Four includes a review of medroxyprogesterone, which is a type of progestin that is used as a long-lasting injectable contraceptive and for the treatment of hormone-dependent tumors. Chapter Five describes synovial fluid, which lubricates and cushions joints during motion, and the effects of viscosupplements on the function of synovial fluid. Lastly, Chapter Six introduces the properties of dopamine acrylamide and discusses its application potential in detail.