| Abstract | Vitamin D is synthesized in skin through a reaction mediated by sunlight, and it is metabolized to 25-hydroxyvitamin D, in liver, and in 1,25-dihydroxyvitamin D, in kidney. This last reaction has a tight feedback mechanism. 1,25-dihydroxyvitamin D is the active hormone, and its actions are mediated mainly by nuclear receptors. Its major functions are in calcium metabolism and bone mass maintenance. Hypovitaminosis D, as a disease in adult people, manifests itself with hypocalcemia and secondary hyperparathyroidism with subsequent loss of trabecular bone, thinning of cortical bone, and, eventually, a higher risk of fractures. Hypovitaminosis D is a very common condition in Europe, Africa, North America and some South American countries, such as Chile and Argentina. Measurement of serum total 25-hydroxyvitamin D concentration is the gold standard to diagnose vitamin D deficiency. Serum concentrations below 50 nmol/L are associated with an increase in parathyroid hormone concentration, and bone loss. Risk factors for vitamin D deficiency, like poor sunlight exposition, aging skin and factors that interfere with normal vitamin D metabolism, are well established. Oral vitamin D supplementation, an easy and inexpensive treatment, is needed to treat this illness. |
| Authors | Melissa Orlandin Premaor, Tania Weber Furlanetto
(Affiliation: Departamento de Medicina Interna, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS.)
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| Journal | Arquivos brasileiros de endocrinologia e metabologia
(Arq Bras Endocrinol Metabol)
Vol. 50
Issue 1
Pg. 25-37
(Feb 2006)
ISSN: 0004-2730 Brazil |
| Vernacular Title | Hipovitaminose D em adultos: entendendo melhor a apresentação de uma velha doença. |
| PMID | 16628272
(Publication Type: English Abstract, Journal Article, Review)
|
| Chemical References |
- Vitamins
- Vitamin D
- 25-hydroxyvitamin D
|
| Topics |
- Adult
- Humans
- Hyperparathyroidism, Secondary
(etiology)
- Hypocalcemia
(etiology)
- Osteoporosis
(etiology)
- Risk Factors
- Severity of Illness Index
- Vitamin D
(administration & dosage, analogs & derivatives, biosynthesis, blood, physiology)
- Vitamin D Deficiency
(complications, diagnosis, epidemiology)
- Vitamins
(administration & dosage)
|
