Normal bone mass and normocalcemia in adulthood despite homozygous vitamin D receptor mutations.
Osteoporos Int
; 26(6): 1819-23, 2015 Jun.
Article
em En
| MEDLINE
| ID: mdl-25708797
ABSTRACT
UNLABELLED Adding to the debate around vitamin D's effects on skeletal health, we report the long-term follow-up of two patients with severe vitamin D receptor mutations, who had normal bone mass acquisition and normalization of calcemia around puberty, suggesting that vitamin D might not be essential for skeletal health in adulthood. INTRODUCTION:
Vitamin D plays a pivotal role in calcium homeostasis, and the consequences of vitamin D insufficiency for skeletal health, as well as the importance of its supplementation, are a matter of great interest. Individuals bearing homozygous vitamin D receptor (VDR) defects present with severe hypocalcemic rickets in early infancy due to vitamin D resistance.METHODS:
Here, we report the follow-up of two patients with hereditary vitamin D-resistant rickets (HVDRR), focusing on bone mass acquisition and evolution of calcemia.RESULTS:
Patient 1 is a 30-year-old male bearing a homozygous p.Arg30* nonsense mutation in the VDR DNA-binding domain, who presented at 6 months. From 9 years of age, treatment requirement decreased progressively. Follow-up with DXA showed normal bone mass acquisition. In adulthood, he maintains normocalcemia without calcium supplementation and has no signs of bone fragility. Patient 2 is a 37-year-old female with milder HVDRR and alopecia due to a homozygous p.Gly319Val mutation in the VDR ligand-binding domain. Around puberty, hypercalciuria and kidney stones were detected, resulting in suspension of treatment. Follow-up with DXA revealed normal bone mass, and she maintained normocalcemia without supplementation during gestation and lactation.CONCLUSIONS:
The long-term follow-up of HVDRR provides insights into the role of vitamin D in human calcium homeostasis and bone health. The normalization of calcemia and normal bone mass acquisition despite a permanently dysfunctional VDR suggest that vitamin D might not be essential for skeletal health in adulthood. Extrapolation of these findings may have implications in broader clinical settings, especially considering widespread vitamin D supplementation.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Densidade Óssea
/
Receptores de Calcitriol
/
Hipercalcemia
/
Mutação
Tipo de estudo:
Observational_studies
/
Prognostic_studies
Idioma:
En
Revista:
Osteoporos Int
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Brasil