Biomaterial Database

Serum free 1,25-dihydroxyvitamin D and the free 1,25-dihydroxyvitamin D index during a longitudinal study of human pregnancy and lactation. 1990

S G Wilson, and R W Retallack, and J C Kent, and G K Worth, and D H Gutteridge

Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia.

The changes in three different indices of 1,25-dihydroxyvitamin D (1,25(OH)2D) biological activity were studied longitudinally in 35 women during late pregnancy and lactation and in 26 control women. Measurements were made of maternal serum total 1,25(OH)2D and free 1,25(OH)2D concentration (by centrifugal ultrafiltration) and the free 1,25(OH)2D index (the molar ratio of total 1,25(OH)2D and vitamin D binding protein (DBP]. During late pregnancy total 1,25(OH)2D concentrations were significantly elevated when compared to controls, as were free 1,25(OH)2D and DBP concentrations and the free 1,25(OH)2D index. Serum total 1,25(OH)2D, free 1,25(OH)2D and DBP concentrations all fell dramatically during the first 2 weeks of lactation with total 1,25(OH)2D and free 1,25(OH)2D concentrations falling to levels below those of controls. During the course of lactation both total 1,25(OH)2D and free 1,25(OH)2D levels rose significantly although they were not different from controls at 18 weeks of lactation. In contrast, the free 1,25(OH)2D index fell during the first 2 weeks of lactation, but remained at this level, significantly lower than controls. Neither urinary calcium excretion nor dietary calcium intake correlated with total or free 1,25(OH)2D, DBP, or the free 1,25(OH)2D index. The disagreement in the results of free 1,25(OH)2D concentration and free 1,25(OH)2D index demonstrates that these two approaches to measuring biologically active 1,25(OH)2D are not equivalent. In attempting to account for the increased calcium requirements of human reproduction we conclude that in pregnancy any of the 1,25(OH)2D measurements may be appropriate. In lactation, however, either 1,25(OH)2D is not a major factor or 1,25(OH)2D biological activity is inadequately represented by any of the currently available methods.

UI	MeSH Term	Description	Entries
D007774	Lactation	The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.	Lactation, Prolonged,Milk Secretion,Lactations, Prolonged,Milk Secretions,Prolonged Lactation,Prolonged Lactations
D008137	Longitudinal Studies	Studies in which variables relating to an individual or group of individuals are assessed over a period of time.	Bogalusa Heart Study,California Teachers Study,Framingham Heart Study,Jackson Heart Study,Longitudinal Survey,Tuskegee Syphilis Study,Bogalusa Heart Studies,California Teachers Studies,Framingham Heart Studies,Heart Studies, Bogalusa,Heart Studies, Framingham,Heart Studies, Jackson,Heart Study, Bogalusa,Heart Study, Framingham,Heart Study, Jackson,Jackson Heart Studies,Longitudinal Study,Longitudinal Surveys,Studies, Bogalusa Heart,Studies, California Teachers,Studies, Jackson Heart,Studies, Longitudinal,Study, Bogalusa Heart,Study, California Teachers,Study, Longitudinal,Survey, Longitudinal,Surveys, Longitudinal,Syphilis Studies, Tuskegee,Syphilis Study, Tuskegee,Teachers Studies, California,Teachers Study, California,Tuskegee Syphilis Studies
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D002117	Calcitriol	The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.	1 alpha,25-Dihydroxycholecalciferol,1 alpha,25-Dihydroxyvitamin D3,1, 25-(OH)2D3,1,25(OH)2D3,1,25-Dihydroxycholecalciferol,1,25-Dihydroxyvitamin D3,1 alpha, 25-dihydroxy-20-epi-Vitamin D3,1,25(OH)2-20epi-D3,1,25-dihydroxy-20-epi-Vitamin D3,20-epi-1alpha,25-dihydroxycholecaliferol,Bocatriol,Calcijex,Calcitriol KyraMed,Calcitriol-Nefro,Decostriol,MC-1288,MC1288,Osteotriol,Renatriol,Rocaltrol,Silkis,Sitriol,Soltriol,Tirocal,1 alpha,25 Dihydroxyvitamin D3,1,25 Dihydroxycholecalciferol,1,25 Dihydroxyvitamin D3,1,25 dihydroxy 20 epi Vitamin D3,Calcitriol Nefro,D3, 1 alpha,25-Dihydroxyvitamin,D3, 1,25-Dihydroxyvitamin,D3, 1,25-dihydroxy-20-epi-Vitamin,KyraMed, Calcitriol,MC 1288
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002136	Calcium, Dietary	Calcium compounds in DIETARY SUPPLEMENTS or in food that supply the body with calcium.	Dietary Calcium
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults