1 / 9

Calcium & Vitamin D: Osteoporosis, Rickets

Calcium & Vitamin D: Osteoporosis, Rickets . By Grace Benson Russell Sage College . Calcium . Most abundant cation in body 40% of body’s mineral mass 1.5%- 2% body weight 99% in bones and teeth 1% intra- and extracellular fluids. Vitamin D. Calciferol Fat- soluble

sona
Download Presentation

Calcium & Vitamin D: Osteoporosis, Rickets

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Calcium & Vitamin D:Osteoporosis, Rickets By Grace Benson Russell Sage College

  2. Calcium • Most abundant cation in body • 40% of body’s mineral mass • 1.5%- 2% body weight • 99% in bones and teeth • 1% intra- and extracellular fluids Vitamin D • Calciferol • Fat- soluble • Derived from steroid; seco- steroid • Two main forms: D2, D3

  3. Calcium Absorption • Ingested as relatively insoluble salts • Absorbed via carrier- mediated active transport, diffusion • Transport regulated by calcitriol – Important! • Three specific mechanisms required for active transport • The amount absorbed varies Calcium Transport/ Function • From blood, deposited in bone for storage to replenish blood calcium if necessary • Bone formation just one of calcium’s important functions in the body: Mineralization • Bone made of organic and inorganic materials; Calcium facilitates interaction = strength

  4. Vitamin D Absorption • No digestion: absorbed from micelle with fat and bile salts • Passive diffusion • Approximately 50% absorbed • Chylomicrons- to lymphatic system- to blood • D3 diffuses from skin into the blood Vitamin D Transport/ Function • DBP – Vitamin D Binding Protein • Goes to tissues and then to liver; obese and overweight store more in adipose = higher doses • Two forms transported slightly differently • Cytochrome P-450 hydroxylases hydroxylate to active form • 25- hydroxylase; found mostly in liver but other tissue as well- first step to 25- OH Vitamin D, calcidiol • Transported back to blood by DBP; storage • 15 day to > 3 week half- life • Vitamin D status

  5. Vitamin D Cont’d • Hydroxylated again by 1- hydroxylase to 1,25- (OH)2 D, Calcitriol= active form • Regulated by enzymes PTH and FGF 23- counteract • DBP- pick up and release • Calcitriol half- life of 2-6 hours • Many body tissues have receptors • Broken down to calcitroic acid via hydroxylation

  6. Osteoporosis • Skeletal disease characterized by deterioration of bone and low bone mineral density • 1 in 2 women; 1 in 4 men will suffer fx • Can be devastating • 80% of sufferers are women • Calcium/ Vitamin D deficiency • Recommendations: • 1,000- 1,200 mg/day Ca • 600 IU, 800 IU Vit. D • Sun exposure Lactose aids Calcium absorption!!

  7. Rickets • Vitamin D deficiency disease • Seizures, growth retardation, failure of bone to mineralize • Epiphyseal plates in infants • Wrists, ankles, knees enlarge • Spine becomes curved • Other deformities • Infants at risk- Vitamin D supplement for breastfed infants • Supplements, mega dose for those deficient

  8. CURRENT NEWS: Return of Rickets in the U.K • Common during the Victorian Era among children who worked in factories • Dr. Sally Davies, Chief Medical Officer, recommends free vitamins to children under 5 • Largely eliminated during the 1950’s (cod liver oil) • Numbers have increased fourfold in the last 15 years • No official surveillance system • Environmental? Cultural? • Preventable!

  9. References Cheng, M. (2013). Rickets making a comeback in the UK, doctors say. Retrieved from http://onlineathens.com/health/2013-11-08/rickets-making-comeback-uk-doctors-say Gropper, S.S., Smith, J.L. (2013). Advanced Nutrition and Human Metabolism. 6th ed. Belmont, CA: Wadsworth. Hansen, C.M., Binderup, L., Hamberg, K.J., Carlberg, C., (2001). VITAMIN D AND CANCER: EFFECTS OF 1,25(OH)2D3 AND ITS ANALOGS ON GROWTH CONTROL AND TUMORIGENESIS. Retrieved from http://www.bioscience.org/2001/v6/d/hansen/figures.htm Inn, D., (2013). Calcium is Important. Retrieved from healthandfashion.US/calcium-is-important New Health Guide. (2013). How Much Calcium do We Need? Retrieved from http://www.newhealthguide.org/how-much-calcium-Do-we-need.html 2011). Retrieved from http://tuesday-johnson.tumblr.com/post/13994711622/ca-1870-1910-portrait-of-a-young-girl-with BBC News. (2012). Cheap vitamin D 'would boost health. Retrieved from http://www.bbc.co.uk/news/health-20710028 WebMD. (2011). Slideshow: A Visual Guide to Osteoporosis. Retrieved from http://www.webmd.com/osteoporosis/ss/slideshow-osteoporosis-overview

More Related