Seasonal fluctuations in serum concentrations of vitamin D metabolites in normal subjects.

Serum concentrations of 25-hydroxycholecalciferol (25-OHD), 24,25-dihydroxycholecalciferol (24,25-(OH)2D), and 1,25-dihydroxycholecalciferol (1,25-(OH)2D) were measured at monthly intervals throughout the year in eight normal subjects. 25-OHD was measured by competitive protein-binding assay after Sephadex LH 20 chromatography, 24,25-(OH)2D by competitive protein-binding assay after Sephadex LH 20 and high-pressure chromatography, and 1,25-(OH)2D by radioimmunoassay after the same separation procedure as for 24,25-(OH)2D. A seasonal variation, apparently dependent on exposure to ultraviolet light, was found for all three metabolites. A study in six other normal subjects showed that there was no diurnal rhythm in any of the metabolites. Oral administration of 2 microgram 1,25-(OH)2D caused a sharp rise in serum concentrations of 1,25-(OH)2D and no change in the concentrations of the two other metabolites, but by 12 hours the 1,25-(OH)2D concentration had returned to the basal value. The concentrations of all three metabolites studied vary according to the season. Thus to interpret these concentrations in any subject the normal range for the particular season must be referred to.

[1]  T. Visser,et al.  SERUM CONCENTRATIONS OF METABOLITES OF VITAMIN D IN PATIENTS WITH CHRONIC RENAL FAILURE (CRF). CONSEQUENCES FOR THE TREATMENT WITH 1‐α‐HYDROXY‐DERIVATIVES , 1981, Clinical endocrinology.

[2]  K R Mahaffey,et al.  Reduction in 1,25-dihydroxyvitamin D in children with increased lead absorption. , 1980, The New England journal of medicine.

[3]  E. Mawer.  Clinical implications of measurements of circulating vitamin D metabolites. , 1980, Clinics in Endocrinology and Metabolism.

[4]  R. Horst,et al.  Elevated Plasma 1,25-(OH)2D Following Massive Dosing of Vitamin D3 in Dairy Cattle , 1979 .

[5]  Y. Weisman,et al.  1α, 25-Dihydroxyvitamin D3, and 24,25-dihydroxyvitamin D3 in vitro synthesis by human decidua and placenta , 1979, Nature.

[6]  E. Mallet,et al.  Serum Concentration of 24, 25-Dihydroxyvitamin D in Normal Children and in Children with Rickets , 1979, Pediatric Research.

[7]  E. Mawer,et al.  1,25-Dihydroxycholecalciferol in human serum and its relationship with other metabolites of vitamin D-3. , 1979, Clinica chimica acta; international journal of clinical chemistry.

[8]  H. DeLuca,et al.  Determination of vitamin D and its metabolites in plasma from normal and anephric man. , 1979, The Biochemical journal.

[9]  J. Eastwood,et al.  PLASMA 1,25(OH2) VITAMIN D CONCENTRATIONS IN NUTRITIONAL OSTEOMALACIA , 1979, The Lancet.

[10]  J. Eastwood,et al.  NORMAL PLASMA-1,25-(OH)2-VITAMIN-D CONCENTRATIONS IN NUTRITIONAL OSTEOMALACIA , 1979, The Lancet.

[11]  M. Scrutton.  Vitamin D: Biochemical, Chemical and Clinical Aspects related to Calcium Metabolism , 1979 .

[12]  T. Cole,et al.  Diet, sunlight, and 25-hydroxy vitamin D in healthy children and adults. , 1979, British medical journal.

[13]  J. Kanis,et al.  The absence of 24,25-dihydroxycholecalciferol in anephric patients. , 1978, Clinical science and molecular medicine. Supplement.

[14]  M. Wills,et al.  SEASONAL VARIATION IN SERUM-25-HYDROXYVITAMIN-D IN THE ELDERLY IN BRITAIN , 1977, The Lancet.

[15]  H. DeLuca,et al.  A sensitive, precise, and convenient method for determination of 1,25-dihydroxyvitamin D in human plasma. , 1976, Archives of biochemistry and biophysics.

[16]  D. Brown,et al.  Seasonal variations in serum 25-hydroxycholecalciferol in healthy people. , 1974, Lancet.

[17]  H. DeLuca,et al.  Stimulation of 24,25-Dihydroxyvitamin D3 Production by 1,25-Dihydroxyvitamin D3 , 1974, Science.

[18]  H. Dyggve.  Comparison between micro-modifications of prothrombin-proconvertin determinations and of the prothrombin time method. , 1958, Scandinavian journal of clinical and laboratory investigation.

[19]  O. J. Malm.  Calcium requirement and adaptation in adult men. , 1958, Scandinavian journal of clinical and laboratory investigation.