Relationship between serum 25-hydroxyvitamin D and parathyroid hormone in the search for a biochemical definition of vitamin D deficiency in children.
Pediatr Res. 2013 Sep 2. doi: 10.1038/pr.2013.139.
Atapattu N, Shaw N, Högler W.
Department of Endocrinology and Diabetes, Birmingham Children's Hospital, Birmingham, United Kingdom.
Background:Current guidelines use differing definitions of vitamin D deficiency based on serum 25-hydroxyvitamin D (25OHD) levels which complicates clinical decision making on vitamin D doses used for prevention and treatment. This study examined the natural relationship between serum 25OHD, parathyroid hormone (PTH), calcium, phosphate and alkaline phosphatase.
Methods:214 children routinely admitted without conditions affecting the natural relationship among metabolites, including 17 with radiologically confirmed vitamin D deficiency rickets, were studied. The frequency of abnormal bone metabolites was examined for different 25OHD thresholds.
Results:The best fitting intersection point where PTH levels increased was a 25OHD level of 34 nmol/l (R2 = 0.454: 95% CI 27-41 nmol/l). 73.3% and 86.1% of children demonstrated some biochemical abnormality below 25OHD levels of 41 nmol/l and 27 nmol/l, respectively. All children with rickets had 25OHD levels < 34 nmol/l. The vast majority of patients with abnormal bone metabolites had 25OHD levels < 34 nmol/l and PTH levels > 50 ng/l.
Conclusions:Vitamin D deficiency, based on PTH elevation, was best defined by a 25OHD level of < 34 nmol/l. Since deficient calcium supply often co-exists with vitamin D deficiency and both can independently cause nutritional rickets, a threshold for the skeletal effects of vitamin D should not be based purely on 25OHD levels.
- Search PTH in VitaminDWiki 779 results as of Sept 2013
- Variations in Parathyroid Hormone Concentrations in Patients with Low Vitamin D – June 2012
- All items in Thyroid and Parathyroid
- PTH does not plateau with increasing vitamin D, but does decrease with patient age – Aug 2012
- Children have PTH problems when vitamin D is less than 15 ng – Nov 2011
- PTH needs vitamin D level higher than 13 ng – Cohort June 2010
- Need 40 ng of vitamin D to have proper PTH levels – May 2011
- Japanese decided that 28 ng mimimum for proper parathyroid hormone – June 2010Vitamin D deficiency for children’s bones is 14ng, based on PTH analysis – Sept 2013
1977 visitors, last modified 11 Sep, 2013,