Christesen HT, Andersen LB Reply to: 'vitamin D deficiency during pregnancy: confronting the issues'. Clin Endocrinol (Oxf). 2014 Jul;81(1):155-6. doi: 10.1111/cen.12328. Epub 2013 Oct 15.
Christesen HT, Elvander C, Lamont RF, Jørgensen JS The impact of vitamin D in pregnancy on extraskeletal health in children: a systematic review. Acta Obstet Gynecol Scand. 2012 Dec;91(12):1368-80. doi: 10.1111/aogs.12006. Review.
Christesen HT, Falkenberg T, Lamont RF, Jørgensen JS The impact of vitamin D on pregnancy: a systematic review. Acta Obstet Gynecol Scand. 2012 Dec;91(12):1357-67. doi: 10.1111/aogs.12000. Epub 2012 Oct 17. Review.
Galthen-Sørensen M, Andersen LB, Sperling L, Christesen HT Maternal 25-hydroxyvitamin D level and fetal bone growth assessed by ultrasound: a systematic review. Ultrasound Obstet Gynecol. 2014 Dec;44(6):633-40. doi: 10.1002/uog.13431. Review.
Vitamin D and Angiogenic Markers in Odense Child Cohort 1: A Prospective Cohort Study on Their Role in Early Pregnancy Adverse Outcome
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.
