Measurement of Vitamin D metabolites: an international perspective on methodology and clinical interpretation

Carter, G.D.; Carter, C.R.; Gunter, Elaine W.; Jones, Julia C.; Jones, Glenville; Makin, H. L. J.; Sufi, S.

doi:10.1016/j.jsbmb.2004.03.055

Cited by 117 publications

(99 citation statements)

References 5 publications

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“…(38) Alkaline phosphatase activity, OC, and IGF-1 were evaluated as absolute values and as SDs adjusted for age using inhouse reference curves established with values obtained in healthy girls, including those presented herein.…”

Section: Biochemical Analysesmentioning

confidence: 99%

“…(38) Samples were measured together with 20 DEQAS controls (range 9 to 79 nmol/L). These control values were -0.11 AE 0.72 SD units (mean AE SD) from the all-laboratories means for each control.…”

Section: Biochemical Analysesmentioning

confidence: 99%

“…(12) Differences in the 25(OH)D assays used might explain some discrepancies, especially because results have not been validated systematically using external control assessment schemes. (37,38) Also, proposals of 25(OH)D cutoffs for adequate and insufficient vitamin D status during growth have not sufficiently taken into consideration possible interplays with calcium intake, which is crucial for bone mass accrual.…”

Section: Introductionmentioning

confidence: 99%

“…(38) Cross-sectional analyses of lumbar spine area bone mineral content (BMC) and areal bone mineral density (aBMD) at baseline and during a 4-year follow-up and of markers of bone and calcium metabolism at baseline enabled the evaluation of a possible interaction of vitamin D status and calcium intake on trabecular bone health during late puberty.…”

Section: Introductionmentioning

confidence: 99%

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Adverse interaction of low-calcium diet and low 25(OH)D levels on lumbar spine mineralization in late-pubertal girls

Esterle

Nguyen

Walrant-Debray

et al. 2010

Journal of Bone and Mineral Research

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No consensus has been reached on the serum 25-hydroxyvitamin D [25(OH)D] levels required to ensure optimal bone health around menarche. We searched for a possible interaction of 25(OH)D levels and calcium intake on lumbar spine mineralization and on biologic features of bone metabolism in healthy late-pubertal girls. Lumbar spine parameters (ie, area, mineral content, and density) and calcium intake were evaluated in 211 healthy white adolescent girls at pubertal stages IV-V (11 to 16.9 years), together with biologic markers of calcium and bone metabolism and with International External Quality Assessment Scheme for Vitamin D Metabolite (DEQAS)-validated serum 25(OH)D levels. A high prevalence of 25(OH)D levels 30 nmol/L (41%), 40 nmol/L (61%), and 50 nmol/L (70%) was found during winter-spring. Parathyroid hormone (PTH) levels were inversely associated with 25(OH)D levels ( p ¼ .0021). In contrast, lumbar spine mineral content and density were not associated with 25(OH)D, excepted when calcium intake was below 600 mg/day ( p ¼ .0081). Girls with such low calcium intake and 25(OH)D levels of 40 nmol/L or less (9% of the cohort) had a 0.4 to 0.7 SD lower mean areal bone mineral density Z-score than girls with higher calcium intake and/or higher 25(OH)D status. The adverse association between lumbar spine mineralization and combined calcium deficiency-low 25(OH)D levels remained significant in the 91 girls who could be followed over 4 years after their initial evaluation. We conclude that low 25(OH)D levels ( 40 nmol/L) are observed frequently during winterspring in late-pubertal European girls, which may exacerbate the negative impact of calcium deficiency on lumbar spine mineralization. ß

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Section: Biochemical Analysesmentioning

confidence: 99%

Section: Biochemical Analysesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Adverse interaction of low-calcium diet and low 25(OH)D levels on lumbar spine mineralization in late-pubertal girls

Esterle

Nguyen

Walrant-Debray

et al. 2010

Journal of Bone and Mineral Research

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“…The organization of DEQAS has been described elsewhere (6 ), and details are available on the DEQAS website (www.deqas.org). In brief, five samples of normal human sera are sent out at 3-month intervals.…”

mentioning

confidence: 99%

How Accurate Are Assays for 25-Hydroxyvitamin D? Data from the International Vitamin D External Quality Assessment Scheme

et al. 2004

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Randomized Controlled Trial of Calcium Supplementation in Healthy, Nonosteoporotic, Older Men

Reid¹,

Ames²,

Mason³

et al. 2008

Arch Intern Med

125

118

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Background: There is no consistent evidence, to our knowledge, that calcium supplementation affects bone mineral density (BMD) in men, despite male osteoporosis being a common clinical problem.Methods: To determine the effects of calcium supplementation (600 mg/d, 1200 mg/d, or placebo) on BMD in men, we conducted a double-blind, randomized controlled trial for a 2-year period at an academic clinical research center. A total of 323 healthy men at least 40 years old (mean age, 57 years) were recruited by newspaper advertisement. Complete follow-up was achieved in 96% of subjects. Results:The BMD increased at all sites in the group receiving calcium, 1200 mg/d, by 1% to 1.5% more than those receiving placebo. The results for the group receiving calcium, 600 mg/d, were not different from the placebo group at any BMD site. There was no interaction between the BMD treatment effect and either age or dietary calcium intake.

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Measurement of Vitamin D metabolites: an international perspective on methodology and clinical interpretation

Cited by 117 publications

References 5 publications

Adverse interaction of low-calcium diet and low 25(OH)D levels on lumbar spine mineralization in late-pubertal girls

Adverse interaction of low-calcium diet and low 25(OH)D levels on lumbar spine mineralization in late-pubertal girls

How Accurate Are Assays for 25-Hydroxyvitamin D? Data from the International Vitamin D External Quality Assessment Scheme

Randomized Controlled Trial of Calcium Supplementation in Healthy, Nonosteoporotic, Older Men

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