Search tips
Search criteria 


Logo of jcinvestThe Journal of Clinical Investigation
J Clin Invest. 1985 August; 76(2): 470–473.
PMCID: PMC423843

Evidence for alteration of the vitamin D-endocrine system in blacks.


As compared with values in white subjects, bone mass is known to be increased and urinary calcium to be diminished in black individuals. To evaluate the possibility that these changes are associated with alterations in the vitamin D-endocrine system, an investigation was performed in 12 black subjects, 7 men and 5 women, and 14 white subjects, 8 men and 6 women, ranging in age from 20 to 35 yr. All of them were hospitalized on a metabolic ward and were given a constant daily diet containing 400 mg of calcium, 900 mg of phosphorus, and 110 meq of sodium. Whereas mean serum calcium, ionized calcium, and phosphate were the same in the two groups, mean serum immunoreactive parathyroid hormone (350 +/- 34 vs. 225 +/- 26 pg/ml, P less than 0.01) and mean serum 1,25-dihydroxyvitamin D (1,25(OH)2D) (41 +/- 3 vs. 29 +/- 2 pg/ml, P less than 0.01) were significantly higher, and mean serum 25-hydroxy-vitamin D (25-OHD) was significantly lower in the blacks than in the whites (6 +/- 1 vs. 20 +/- 2 ng/ml, P less than 0.001). Mean urinary sodium and 24-h creatinine clearance were the same in the two groups, whereas mean urinary calcium was significantly lower (101 +/- 14 vs. 166 +/- 13 mg/d, P less than 0.01) and mean urinary cyclic AMP was significantly higher (3.11 +/- 0.47 vs. 1.84 +/- 0.25 nM/dl glomerular filtrate, P less than 0.01) in the blacks. Further, the blacks excreted an intravenous calcium load, 15 mg/kg body weight, as efficiently as the whites (49 +/- 3 vs. 53 +/- 3%, NS). Mean serum Gla protein was lower in blacks than in whites (14 +/- 2 vs. 24 +/- 3 ng/ml, P less than 0.02), and increased significantly in both groups in response to 1,25(OH)2D3, 4 micrograms/d for 4 d. There was a blunted response of urinary calcium to 1,25(OH)2D3 in the blacks, and mean serum calcium did not change. The results indicate that alteration of the vitamin D-endocrine system with enhanced renal tubular reabsorption of calcium and increased circulating 1,25(OH)2D as a result of secondary hyperparathyroidism may contribute to the increased bone mass in blacks. Their low serum 25-OHD is attributed to diminished synthesis of vitamin D in the skin because of increased pigment.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (783K), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • TROTTER M, BROMAN GE, PETERSON RR. Densites of bones of white and Negro skeletons. J Bone Joint Surg Am. 1960 Jan;42-A:50–58. [PubMed]
  • Cohn SH, Abesamis C, Yasumura S, Aloia JF, Zanzi I, Ellis KJ. Comparative skeletal mass and radial bone mineral content in black and white women. Metabolism. 1977 Feb;26(2):171–178. [PubMed]
  • Garn SM, Sandusky ST, Nagy JM, McCann MB. Advanced skeletal development in low-income Negro children. J Pediatr. 1972 Jun;80(6):965–969. [PubMed]
  • Owen GM, Lubin AH. Anthropometric differences between black and white preschool children. Am J Dis Child. 1973 Aug;126(2):168–169. [PubMed]
  • Garn SM, Clark DC, Trowbridge FL. Tendency toward greater stature in American black children. Am J Dis Child. 1973 Aug;126(2):164–166. [PubMed]
  • Garn SM, Clark DC. Nutrition, growth, development, and maturation: findings from the ten-state nutrition survey of 1968-1970. Pediatrics. 1975 Aug;56(2):306–319. [PubMed]
  • Baginski ES, Marie SS, Clark WL, Zak B. Direct microdetermination of serum calcium. Clin Chim Acta. 1973 Jun 14;46(1):49–54. [PubMed]
  • Bartels H, Böhmer M. Eine Mikromethode zur Kreatininbestimmung. Clin Chim Acta. 1971 Mar;32(1):81–85. [PubMed]
  • Dorantes LM, Arnaud SB, Arnaud CD. Importance of the isolation of 25-hydroxyvitamin D before assay. J Lab Clin Med. 1978 May;91(5):791–796. [PubMed]
  • Reinhardt TA, Horst RL, Orf JW, Hollis BW. A microassay for 1,25-dihydroxyvitamin D not requiring high performance liquid chromatography: application to clinical studies. J Clin Endocrinol Metab. 1984 Jan;58(1):91–98. [PubMed]
  • Wiske PS, Epstein S, Bell NH, Queener SF, Edmondson J, Johnston CC., Jr Increases in immunoreactive parathyroid hormone with age. N Engl J Med. 1979 Jun 21;300(25):1419–1421. [PubMed]
  • Epstein S, Poser J, McClintock R, Johnston CC, Jr, Bryce G, Hui S. Differences in serum bone GLA protein with age and sex. Lancet. 1984 Feb 11;1(8372):307–310. [PubMed]
  • Gilman AG. A protein binding assay for adenosine 3':5'-cyclic monophosphate. Proc Natl Acad Sci U S A. 1970 Sep;67(1):305–312. [PubMed]
  • Broadus AE, Mahaffey JE, Bartter FC, Neer RM. Nephrogenous cyclic adenosine monophosphate as a parathyroid function test. J Clin Invest. 1977 Oct;60(4):771–783. [PMC free article] [PubMed]
  • Price PA, Parthemore JG, Deftos LJ. New biochemical marker for bone metabolism. Measurement by radioimmunoassay of bone GLA protein in the plasma of normal subjects and patients with bone disease. J Clin Invest. 1980 Nov;66(5):878–883. [PMC free article] [PubMed]
  • Bell NH, Shaw S, Turner RT. Evidence that 1,25-dihydroxyvitamin D3 inhibits the hepatic production of 25-hydroxyvitamin D in man. J Clin Invest. 1984 Oct;74(4):1540–1544. [PMC free article] [PubMed]
  • Clemens TL, Adams JS, Henderson SL, Holick MF. Increased skin pigment reduces the capacity of skin to synthesise vitamin D3. Lancet. 1982 Jan 9;1(8263):74–76. [PubMed]
  • Teitelbaum SL, Halverson JD, Bates M, Wise L, Haddad JG. Abnormalities of circulating 25-OH vitamin D after jejunal-lleal bypass for obesity: evidence of an adaptive response. Ann Intern Med. 1977 Mar;86(3):289–293. [PubMed]
  • Dalén N, Hallberg D, Lamke B. Bone mass in obese subjects. Acta Med Scand. 1975 May;197(5):353–355. [PubMed]
  • Luft FC, Grim CE, Fineberg N, Weinberger MC. Effects of volume expansion and contraction in normotensive whites, blacks, and subjects of different ages. Circulation. 1979 Apr;59(4):643–650. [PubMed]
  • Rude RK, Bethune JE, Singer FR. Renal tubular maximum for magnesium in normal, hyperparathyroid, and hypoparathyroid man. J Clin Endocrinol Metab. 1980 Dec;51(6):1425–1431. [PubMed]
  • 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 Sep;64(3):729–736. [PMC free article] [PubMed]

Articles from The Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation