Surgery — Vitamin D and the Free Hormone Hypothesis
Citation(s)
Blomberg Jensen M Vitamin D and male reproduction. Nat Rev Endocrinol. 2014 Mar;10(3):175-86. doi: 10.1038/nrendo.2013.262. Epub 2014 Jan 14. Review.
Bogunovic L, Kim AD, Beamer BS, Nguyen J, Lane JM Hypovitaminosis D in patients scheduled to undergo orthopaedic surgery: a single-center analysis. J Bone Joint Surg Am. 2010 Oct 6;92(13):2300-4. doi: 10.2106/JBJS.I.01231.
Brandt MR, Kehlet H, Skovsted L, Hansen JM Rapid decrease in plasma-triiodothyronine during surgery and epidural analgesia independent of afferent neurogenic stimuli and of cortisol. Lancet. 1976 Dec 18;2(7999):1333-6.
Rem J, Nielsen OS, Brandt MR, Kehlet H Release mechanisms of postoperative changes in various acute phase proteins and immunoglobulins. Acta Chir Scand Suppl. 1980;502:51-6.
Zaloga GP, Butterworth JF 4th Hypovitaminosis D in hospitalized patients: a marker of frailty or a disease requiring treatment? Anesth Analg. 2014 Sep;119(3):613-8. doi: 10.1213/ANE.0000000000000368.
Vitamin D and the Free Hormone Hypothesis: Lessons From Surgical Stress
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
