Related Experiment Videos
[The usefulness of calcium and vitamin D supplementation after the Women's Health Initiative trial]
Leif Mosekilde1, Bente Lomholt Langdahl, Lars Rejnmark Nielsen
1Arhus Sygehus, Medicinsk-endokrinologisk Afdeling C, Arhus C. leif.mosekilde@as.aaa.dk
Abstract:
Three recently published randomized controlled studies on the effects of calcium and vitamin D on fracture risk from the UK and the USA were critically reviewed. We found problems related to their external validity compromising their transferability to Denmark. Furthermore, study power was limited because of the selection of low-risk patients, problems with compliance and persistence, and supplementation with calcium and vitamin D outside the protocol. Two recent meta-analyses including the three studies supported the continuous use of calcium and vitamin D to prevent fractures in the elderly.
Related Concept Videos
Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and case-control studies.
Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
Skeleton and Calcium Homeostasis
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
Essential Minerals for Bone Health
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...