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Logo of jcinvestThe Journal of Clinical Investigation
J Clin Invest. 1974 August; 54(2): 287–296.
PMCID: PMC301556



Serum immunoreactive parathyroid hormone (iPTH) and plasma total calcium, ionized calcium, magnesium, and phosphorus levels were determined during the first 9 days of life in 137 normal term infants, 55 “sick” infants, and 43 hypocalcemic (Ca <7.5 mg/100 ml; Ca++<4.0 mg/100 ml) infants.

In the cord blood, elevated levels of plasma Ca++ and Ca were observed, while levels of serum iPTH were either undetectable or low. In normal newborns during the first 48 h of life there was a decrease in plasma Ca and Ca++, while the serum iPTH level in most samples remained undetectable or low; after 48 h there were parallel increases in plasma Ca and Ca++ and serum iPTH levels. Plasma Mg and P levels increased progressively after birth in normal infants.

In the sick infants, plasma Ca, Ca++ and P levels were significantly lower than in the normal newborns, while no significant differences were found in the plasma Mg levels. The general pattern of serum iPTH levels in the sick infants was similar to that observed in the normal group, though there was a tendency for the increase in serum iPTH to occur earlier and for the iPTH levels to be higher in the sick infants.

In the hypocalcemic infants, plasma Mg levels were consistently lower than in the normal infants after 24 h of age, while no significant differences were found in the plasma P levels. Hyperphosphatemia was uncommon and did not appear to be a contributing factor in the pathogenesis of hypocalcemia in most infants. Most of the hypocalcemic infants, including those older than 48 h, had inappropriately low serum iPTH levels.

Evidence obtained from these studies indicates that parathyroid secretion is normally low in the early new born period and impaired parathyroid function, characterized by undetectable or low serum iPTH, is present in most infants with neonatal hypocalcemia. Additional unknown factors appear to contribute to the lowering of plasma Ca in the neonatal period. The net effect of unknown plasma hypocalcemic factor(s) on the one hand and parathyroid activity on the other may account for differences in plasma Ca levels observed between normal, sick, and hypocalcemic infants. Depressed plasma Mg is frequently present in hypocalcemic infants. To what degree the hypomagnesemia reflects parathyroid insufficiency or the converse, to what degree parathyroid insufficiency and hypocalcemia are secondary to hypomagnesemia, is uncertain.

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Selected References

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  • Anast CS, Mohs JM, Kaplan SL, Burns TW. Evidence for parathyroid failure in magnesium deficiency. Science. 1972 Aug 18;177(4049):606–608. [PubMed]
  • Suh SM, Tashjian AH, Jr, Matsuo N, Parkinson DK, Fraser D. Pathogenesis of hypocalcemia in primary hypomagnesemia: normal end-organ responsiveness to parathyroid hormone, impaired parathyroid gland function. J Clin Invest. 1973 Jan;52(1):153–160. [PMC free article] [PubMed]
  • Dubowitz LM, Dubowitz V, Goldberg C. Clinical assessment of gestational age in the newborn infant. J Pediatr. 1970 Jul;77(1):1–10. [PubMed]
  • Conaway HH, Anast CS. Double-antibody radioimmunoassay for parathyroid hormone. J Lab Clin Med. 1974 Jan;83(1):129–138. [PubMed]
  • Canterbury JM, Reiss E. Multiple immunoreactive molecular forms of parathyroid hormone in human serum. 1. Proc Soc Exp Biol Med. 1972 Sep;140(4):1393–1398. [PubMed]
  • Habener JF, Powell D, Murray TM, Mayer GP, Potts JT., Jr Parathyroid hormone: secretion and metabolism in vivo. Proc Natl Acad Sci U S A. 1971 Dec;68(12):2986–2991. [PubMed]
  • Goldsmith RS, Furszyfer J, Johnson WJ, Fournier AE, Sizemore GW, Arnaud CD. Etiology of hyperparathyroidism and bone disease during chronic hemodialysis. 3. Evaluation of parathyroid suppressibility. J Clin Invest. 1973 Jan;52(1):173–180. [PMC free article] [PubMed]
  • Moore EW. Ionized calcium in normal serum, ultrafiltrates, and whole blood determined by ion-exchange electrodes. J Clin Invest. 1970 Feb;49(2):318–334. [PMC free article] [PubMed]
  • MOSES LE. Statistical theory and research design. Annu Rev Psychol. 1956;7:233–258. [PubMed]
  • GITTLEMAN IF, PINCUS JB, SAITO M, SCHMERZLER E. Hypocalcemia occurring on the first day of life in mature and premature infants. Pediatrics. 1956 Nov;18(5):721–729. [PubMed]
  • Keen JH. Significance of hypocalcaemia in neonatal convulsions. Arch Dis Child. 1969 Jun;44(235):356–361. [PMC free article] [PubMed]
  • Tsang RC, Oh W. Neonatal hypocalcemia in low birth weight infants. Pediatrics. 1970 May;45(5):773–781. [PubMed]
  • Shami Y, Radde IC. Calcium-stimulated ATPase of guinea pig placenta. Biochim Biophys Acta. 1971 Dec 3;249(2):345–352. [PubMed]
  • BOYD JD. Development of the thyroid and parathyroid glands and the thymus. Ann R Coll Surg Engl. 1950 Dec;7(6):455–471. [PMC free article] [PubMed]
  • Garel JM. Effet de l'injection d'un sérum "anti-parathormone" chez le foetus de rat. C R Acad Sci Hebd Seances Acad Sci D. 1970 Dec 21;271(25):2364–2366. [PubMed]
  • Smith FG, Jr, Alexander DP, Buckle RM, Britton HG, Nixon DA. Parathyroid hormone in foetal and adult sheep: the effect of hypocalcaemia. J Endocrinol. 1972 Jun;53(3):339–348. [PubMed]
  • Tan CM, Raman A, Sinnathyray TA. Serum ionic calcium levels during pregnancy. J Obstet Gynaecol Br Commonw. 1972 Aug;79(8):694–697. [PubMed]
  • Cushard WG, Jr, Creditor MA, Canterbury JM, Reiss E. Physiologic hyperparathyroidism in pregnancy. J Clin Endocrinol Metab. 1972 May;34(5):767–771. [PubMed]
  • Graham RW, Scothorne RJ. Calcium homeostasis in the foetal guinea pig. Q J Exp Physiol Cogn Med Sci. 1970 Jan;55(1):44–53. [PubMed]
  • Graham RW, Porter GP. Fetal-maternal plasma calcium relationships in the rabbit. Q J Exp Physiol Cogn Med Sci. 1971 Jul;56(3):160–168. [PubMed]
  • CONNELLY JP, CRAWFORD JD, WATSON J. Studies of neonatal hyperphosphatemia. Pediatrics. 1962 Sep;30:425–432. [PubMed]
  • Linarelli LG. Newborn urinary cyclic AMP and developmental renal responsiveness to parathyroid hormone. Pediatrics. 1972 Jul;50(1):14–23. [PubMed]
  • Tsang RC, Kleinman LI, Sutherland JM, Light IJ. Hypocalcemia in infants of diabetic mothers. Studies in calcium, phosphorus, and magnesium metabolism and parathormone responsiveness. J Pediatr. 1972 Mar;80(3):384–395. [PubMed]
  • GRAHAM GG, BARNESS LA, GYORGY P. Serum calcium and inorganic phosphate in the newborn infant, and their relation to different feedings. J Pediatr. 1953 Apr;42(4):401–408. [PubMed]
  • CRAIG WS. Clinical signs of neonatal tetany: with especial reference to their occurrence in newborn babies of diabetic mothers. Pediatrics. 1958 Aug;22(2):297–308. [PubMed]
  • Paunier L, Radde IC, Kooh SW, Conen PE, Fraser D. Primary hypomagnesemia with secondary hypocalcemia in an infant. Pediatrics. 1968 Feb;41(2):385–402. [PubMed]
  • Estep H, Shaw WA, Watlington C, Hobe R, Holland W, Tucker SG. Hypocalcemia due to hypomagnesemia and reversible parathyroid hormone unresponsiveness. J Clin Endocrinol Metab. 1969 Jun;29(6):842–848. [PubMed]
  • Muldowney FP, McKenna TJ, Kyle LH, Freaney R, Swan M. Parathormone-like effect of magnesium replenishment in steatorrhea. N Engl J Med. 1970 Jan 8;282(2):61–68. [PubMed]
  • Jones KH, Fourman P. Effects of infusions of magnesium and of calcium in parathyroid insufficiency. Clin Sci. 1966 Feb;30(1):139–150. [PubMed]

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