Background/Aims: While numerous studies have examined 25(OH)-vitamin D3 (25-D) concentrations and their relation to parathyroid hormone (PTH) levels there is only limited information on the interrelation between 25-D, 1,25(OH)2-vitamin D3 (1,25-D) and PTH. It was the aim of this study to assess the vitamin D endocrine system and its relation to age and body mass index (BMI). Methods: This cross-sectional study comprised a convenience sample of 483 adults which attended the endocrinology outpatient service of a university hospital in the years 2002–2004. Results: The mean concentrations of 25-D, 1,25-D, calcium and PTH were 21.0 ± 10.6 ng/ml, 47.9 ± 21.7 pg/ml, 9.48 ± 0.48 mg/dl and 51.0 ± 27.2 pg/ml, respectively. 25-D was related (p < 0.01) to BMI, age, PTH and 1,25-D. After correction for 25-D, we found no relation between BMI and 1,25-D. PTH was related (p < 0.01) to serum calcium, BMI, age and 1,25-D (p = 0015). There was a seasonal variation in both, 25-D and 1,25-D serum concentrations: 25-D levels were lowest in January and increased until July while the nadir and zenith of 1,25-D were found in April and October, respectively. Conclusion: Since BMI was negatively related to 25-D the prevalence of 25-D deficiency (<8.8 ng/ml) increased from 8.8% in subjects with BMI <30 kg/m2 to 15.0% in subjects with BMI >30 kg/m2. BMI, age and season should be taken into account when assessing a patients vitamin D status and more aggressive vitamin D supplementation should be considered for obese subjects.

1.
Steenbock H: The induction of growth promoting and calcifying properties in a ration by exposure to light. Science 1924;60:224–225.
2.
DeLuca HF: Overview of general physiologic features and functions of vitamin D. Am J Clin Nutr 2004;80:1689S–1696S.
3.
Heaney RP: Lessons for nutritional science from vitamin D. Am J Clin Nutr 1999;69:825–826.
4.
Heaney RP: Functional indices of vitamin D status and ramifications of vitamin D deficiency. Am J Clin Nutr 2004;80:1706S–1709S.
5.
Plotnikoff GA, Quigley JM: Prevalence of severe hypovitaminosis D in patients with persistent, nonspecific musculoskeletal pain. Mayo Clin Proc 2003;78:1463–1470.
6.
Thomas MK, Lloyd-Jones DM, Thadhani RI, Shaw AC, Deraska DJ, Kitch BT, Vamvakas EC, Dick IM, Prince RL, Finkelstein JS: Hypovitaminosis D in medical inpatients. N Engl J Med 1998;338:777–783.
7.
Chapuy MC, Preziosi P, Maamer M, Arnaud S, Galan P, Hercberg S, Meunier PJ: Prevalence of vitamin D insufficiency in an adult normal population. Osteoporos Int 1997;7:439–443.
8.
Guillemant J, Taupin P, Le HT, Taright N, Allemandou A, Peres G, Guillemant S: Vitamin D status during puberty in French healthy male adolescents. Osteoporos Int 1999;10:222–225.
9.
Dawson-Hughes B, Dallal GE, Krall EA, Harris S, Sokoll LJ, Falconer G: Effect of vitamin D supplementation on wintertime and overall bone loss in healthy postmenopausal women. Ann Intern Med 1991;115:505–512.
10.
Stamp TC, Round JM: Seasonal changes in human plasma levels of 25-hydroxyvitamin D. Nature 1974;247:563–565.
11.
Mosekilde L: Vitamin D and the elderly. Clin Endocrinol (Oxf) 2005;62:265–281.
12.
Lips P: Vitamin D deficiency and secondary hyperparathyroidism in the elderly: consequences for bone loss and fractures and therapeutic implications. Endocr Rev 2001;22:477–501.
13.
Omdahl JL, Garry PJ, Hunsaker LA, Hunt WC, Goodwin JS: Nutritional status in a healthy elderly population: vitamin D. Am J Clin Nutr 1982;36:1225–1233.
14.
Parikh SJ, Edelman M, Uwaifo GI, Freedman RJ, Semega-Janneh M, Reynolds J, Yanovski JA: The relationship between obesity and serum 1,25-dihydroxy vitamin D concentrations in healthy adults. J Clin Endocrinol Metab 2004;89:1196–1199.
15.
Rucker D, Allan JA, Fick GH, Hanley DA: Vitamin D insufficiency in a population of healthy western Canadians. CMAJ 2002;166:1517–1524.
16.
Lips P, Duong T, Oleksik A, Black D, Cummings S, Cox D, Nickelsen T: A global study of vitamin D status and parathyroid function in postmenopausal women with osteoporosis: baseline data from the multiple outcomes of raloxifene evaluation clinical trial. J Clin Endocrinol Metab 2001;86:1212–1221.
17.
Kudlacek S, Schneider B, Peterlik M, Leb G, Klaushof er K, Weber K, Woloszczuk W, Willvonseder R: Assessment of vitamin D and calcium status in healthy adult Austrians. Eur J Clin Invest 2003;33:323–331.
18.
König J, Elmadfa I: Status of calcium and vitamin D of different population groups in Austria. Int J Vitam Nutr Res 2000;70:214–220.
19.
Bell NH, Epstein S, Greene A, Shary J, Oexmann MJ, Shaw S: Evidence for alteration of the vitamin D-endocrine system in obese subjects. J Clin Invest 1985;76:370–373.
20.
Snijder MB, van Dam RM, Visser M, Deeg DJ, Dekker JM, Bouter LM, Seidell JC, Lips P: Adiposity in relation to vitamin d status and parathyroid hormone levels: a population-based study in older men and women. J Clin Endocrinol Metab 2005;90:4119–4123.
21.
Wortsman J, Matsuoka LY, Chen TC, Lu Z, Holick MF: Decreased bioavailability of vitamin D in obesity. Am J Clin Nutr 2000;72:690–693.
22.
Compston JE, Vedi S, Ledger JE, Webb A, Gazet JC, Pilkington TR: Vitamin D status and bone histomorphometry in gross obesity. Am J Clin Nutr 1981;34:2359–2363.
23.
Zemel MB, Thompson W, Milstead A, Morris K, Campbell P: Calcium and dairy acceleration of weight and fat loss during energy restriction in obese adults. Obes Res 2004;12:582–590.
24.
Shi H, Dirienzo D, Zemel MB: Effects of dietary calcium on adipocyte lipid metabolism and body weight regulation in energy-restricted aP2-agouti transgenic mice. FASEB J 2001;15:291–293.
25.
McCarty MF, Thomas CA: PTH excess may promote weight gain by impeding catecholamine-induced lipolysis-implications for the impact of calcium, vitamin D, and alcohol on body weight. Med Hypotheses 2003;61:535–542.
26.
Bolland MJ, Grey AB, Gamble GD, Reid IR: Association between primary hyperparathyroidism and increased body weight: a meta-analysis. J Clin Endocrinol Metab 2005;90:1525–1530.
27.
Sherman SS, Hollis BW, Tobin JD: Vitamin D status and related parameters in a healthy population: the effects of age, sex, and season. J Clin Endocrinol Metab 1990;71:405–413.
28.
Gallagher JC, Riggs BL, Eisman J, Hamstra A, Arnaud SB, DeLuca HF: Intestinal calcium absorption and serum vitamin D metabolites in normal subjects and osteoporotic patients: effect of age and dietary calcium. J Clin Invest 1979;64:729–736.
29.
Orwoll ES, Meier DE: Alterations in calcium, vitamin D, and parathyroid hormone physiology in normal men with aging: relationship to the development of senile osteopenia. J Clin Endocrinol Metab 1986;63:1262–1269.
30.
Ockene IS, Chiriboga DE, Stanek EJ 3rd, Harmatz MG, Nicolosi R, Saperia G, Well AD, Freedson P, Merriam PA, Reed G, Ma Y, Matthews CE, Hebert JR: Seasonal variation in serum cholesterol levels: treatment implications and possible mechanisms. Arch Intern Med 2004;164:863–870.
31.
Linden V: Vitamin D and serum cholesterol. Scand J Soc Med 1975;3:83–85.
32.
Bostick RM, Fosdick L, Grandits GA, Grambsch P, Gross M, Louis TA: Effect of calcium supplementation on serum cholesterol and blood pressure. A randomized, double-blind, placebo-controlled, clinical trial. Arch Fam Med 2000;9:31–38.
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