Vitamin D deficiency in pregnant women and newborn A Sachan Asst Professor, Dept of Endocrinology SVIMS, Tirupati Good afternoon everybody, I am presenting my data on vitamin D deficiency in north Indian pregnant women and their newborns. This study was conducted at the Sanjay Gandhi postgraduate Institute of medical sciences and Queen Mary’s hospital, Lucknow, India.

Introduction Vitamin D deficiency unexpected in a tropical country with abundant sunshine. Hypovitaminosis D resulting in severe osteomalacia in adolescents has been observed Natl Med J India 2003;16:139-42 We know that pregnancy is associated with increased demand of calcium and subclinical deficiency can become overt during pregnancy. Despite abundant sunshine we have demonstrated hypovitaminosis D in adolescence, a high risk group for vitamin D deficeincy. Possible contributory factors being poor outdoor activity and traditional clothing, leading to poor sun exposure. Calcium deficiency per se can cause secondary hypovitaminosis D.

Introduction Possible contributory factors: Poor outdoor activity / sun exposure / traditional clothing Air pollution Skin pigmentation

Introduction Milk and milk products, the source of calcium, are expensive in India Deficient calcium intake results in childhood rickets and adolescent osteomalacia with healing on dietary calcium replenishment J Trop Pediatr 2003;49:201-6 Arch Dis Child 2003;88:812–7 N Engl J Med 1999;341:563– 8 Calcium supplementation is a standard practice in antenatal clinics in urban area of India, but not in rural area. Natural sources of calcium, like milk and milk products, are prohobitively expensive in India. Routine vitamin D supplementation and fortification is not practised in India, however rural women tend to get more sun exposure due to extensive outdoor activity.

Introduction Experimental study in a rat model Calcium deficiency   PTH   1,25(OH)2D   conversion of vitamin D to polar metabolites in liver  vitamin D deficiency Calcium replenishment   vitamin D Nature 1987;325:62-65

Introduction Active trans-placental transport of calcium to the developing fetus during pregnancy Hypovitaminosis D during pregnancy fetal hypovitaminosis D neonatal rickets and tetany infantile rickets Infantile rickets is associated with high prevalence of lower respiratory tract infections, the largest cause of infant mortality

Introduction ↓ whole-body and lumbar-spine BMCin children Lancet 2006;367:36-43

Introduction Other effects on neonates ↑ risk of bronchial asthma Am J Clin Nutr 2007;85:853-9 Diabetes related autoimmunity Pediatr Diabetes 2007;8:11-4 ↓ length at birth and 1-min Apgar Gynecol Endocrinol 2006;22:585-9

Aims to determine the prevalence of clinical or biochemical osteomalacia & maternal & fetal hypovitaminosis D among urban and rural north Indian women and to study the correlation of those prevalences with calcium intake, sun exposure, serum 25(OH)D, and plasma intact parathyroid hormone (PTH) Aims of the present study were to study the prevalence of hypovitaminosis D among pregnant women and to correlate vitamin D status with sun exposure, daily calcium (dietary plus supplemental) intake, serum intact parathormone (iPTH), and neonates’ serum 25(OH)D.

Material and Methods Subjects: all women with full-term live pregnancy presenting to the hospital and their infants Recruitment from Sept to Nov Exclusion criteria Chronic liver disease Renal disease Treatment with antitubercular drugs Treatment with antiepileptic drugs

Material and Methods Registered 207 subjects out of 572 women 157 Hindu 50 Muslim 29 women practiced purdah

Material and Methods Obstetric / dietary / sun exposure history Any complaints s/o osteomalacia Physical examination of all subjects Daily calcium & vitamin D intake: Dietary calcium & vitamin D intake (food frequency questionnaire) Supplemental calcium intake Detailed dietary and sunexposure history was asked of each subject and physical examination was performed. Daily calcium intake was calculated as the sum of dietary calcium intake and daily supplemental calcium intake. Dietary calcium intake was assessed with a food frequency questionnaire

Material and Methods Daily sun exposure over winter and summer months* Expressed as hours of exposure per day X body surface area exposed Daily sun exposure was assessed separately over winter and summer months and expressed as sun exposure per day in minutes, while exposing face and both forearms Neonatal anthropometry of babies born to the subjects was also performed

Material and Methods Maternal peripheral venous sample Heat labile alkaline phosphatase (HLAP)* 25-hydroxyvitamin D {25(OH)D} Total serum calcium (Ca) corrected for albumin, if < 4 gm / dl Inorganic phosphorus (iP) intact parathormone (iPTH) (n=157) *HLAP = total SAP - heat stable SAP (56oC for 15 min) Peripheral venous samples were collected from each subject and were analysed for serum heat labile alkaline phosphatase, 25-hydroxyvitamin D, total serum calcium and inorganic phosphorus (iP). Serum albumin was also analysed and if found low (below 4 gm/dl), total calcium was corrected for albumin. Anticoagulated blood was collected on ice for plasma intact parathormone (iPTH).

Material and Methods Cord blood sample (n=117) serum alkaline phosphatase (SAP) 25(OH)D Upper limit of normal for HLAP <125 U/L, Cord blood SAP <165 U/L Cord blood samples were collected from neonates born to subjects and were analysed for serum alkaline phosphatase and 25(OH)D. Upper limit of normal for heat labile alkaline phosphatase being 125 U/L and 165 U/L for cord blood.

Material and Methods Serum Ca, Albumin, iP, SAP/HLAP: Spectrophotometry 25(OH)D: RIA (Diasorin) iPTH IRMA (DSL)

Statistical analysis SPSS for windows, release 9.0 Comparison of proportions: 2 test Data log transformed, means compared with Student’s t test Correlation coefficient: Spearman coefficient Cut off of 25(OH)D: Linear regression analysis Two tailed significance level: 0.05 Statistical analysis was done using SPSS software.

Results Registered and not registered subjects Registered Not registered (n= 207) (n 365) Age (y) 24.04.11 24.75.1 Weight (kg) 55.16.5 52.54.3 Parity 1.11.2 1.81.12* Birth weight (kg) 2.91.7 2.72.02* Hindu/Muslim 157/50 267/98 * P<0.001 (Student’s t test)

Results No subject had clinical e/o osteomalacia Biochemical osteomalacia in 29 (14%) subjects

Sub with & without biochemical osteomalacia (HLAP>125) Subjects with Subjects without osteomalacia(n=29) osteomalacia (n=178) Ca (mg/dL) 9.4±0.62 9.4±0.7 iP (mg/dL) 3.6±1.2 4.2±1.73* 25(OH)D 12.1±8.0 14.3±9.5 (ng/mL) Maternal 26 (89.7) 148 (83.1) hypovitaminosis D {25(OH)D < 22.5 ng/ml} iPTH (pg/mL) 127±180(n=24) 74±897(n=133)** *p<0.05 **P<0.005

Sub with & without biochemical osteomalacia (HLAP>125) Subjects with Subjects without osteomalacia(n=29) osteomalacia (n=178) Cord blood 8.1±7.4 8.5±5.4 25(OH)D (ng/mL) Daily calcium 813±435 737±466 intake (mg/d) Daily calcium 22 (75.8) 138 (77.5) intake<RDA Sun exposure 4.9±4.5 6.2±6.0 score over past 3 mo (h/d X % BSA exposed)

Results Subjects with Subjects with 25(OH)D<10ng/ml 25(OH)D>10 (n=88, 42.5%) ng/ml iPTH 125±153 51±39 (pg/ml) P<0.001 Cord blood 5.2±3.0 11.8±5.9 25(OH)D (ng/ml) P<0.001 Out of 207 subjects 68 were rural and 139 were urban and iPTH was available in 157 of them. 117 cord blood samples were analysed. A large number of subjects had hypovitaminosis D. 42% of the subjects and 72 % of the neonates had low vitamin D levels, while alkaline phosphatase was elevated in 14% of the subjects and 14% the babies. 77% of the subjects had daily calcium intake which was less than the recommended daily intake of 1200 mg / day.

Results Correlations Maternal 25(OH)D with cord blood 25(OH)D r= 0.79, P<0.001 Maternal 25(OH)D with iPTH r= -0.35, P<0.001 HLAP with cord blood AP r= 0.19, P<0.05

Correlation: maternal 25(OH)D with iPTH

Results Regression equation: Linear regression equation: iPTH= [-3.32 X 25(OH)D] + 129.76 Cutoff of 25(OH)D= 22.5 ng/ml Number of subjects with 25(OH)D <22.5 ng/ml: 174 (84%)

Results: Comparison of urban and rural subjects Urban Rural p (n=140) (n=67) Sun exposure 3 months 4.1  3.2 9.7  8.1 <0.001 1 year 7.5  5.6 11.6  8.4 0.005 Calcium intake (mg/day) 842  459 549  404 <0.001

Results: Comparison of urban and rural subjects Urban Rural p (n=140) (n=67) Calcium intake 101 (72%) 59 (88%) <0.05 <RDA (1200 mg/day) Vit D intake 16.4  7.4 16.5  7.6 NS (IU/day) HLAP (U/L) 87  60 73  31 NS

Results: Comparison of urban and rural subjects Urban Rural p (n=140) (n=67) Osteomalacia 24 (17%) 5 (7%) NS (HLAP > 125 U/L) 25(OH)D (ng/ml) 14.0  9.5 14.1  8.9 NS Hypovitaminosis D 118 (84%) 56 (84%) NS {25(OH)D < 22.5 ng/ml} iPTH (pg/ml) 94  127 57  49 NS

Results Total daily calcium intake, HLAP, 25(OH)D, and iPTH did not differ between subjects practicing purdah and those not practicing purdah

Results Neonates’ mean cord blood 25(OH)D: 8.45.7 ng/ml 112/117 (96%) neonates were vitamin D deficient No difference in AP between babies born to mothers with normal or low 25(OH)D

Other studies on Asian pregnant subjects Authors Subjects N 25(OH)D (ng/ml) Goswami Indian (Delhi) 29 8.764.3 Heckmatt Asian (U.K.) 44 5.71.3 Brunvand Pakistani 80 7.6 Atiq Pakistani 62 12.89.0

Summary High prevalence of hypovitaminosis D in pregnant women. Correlation of 25(OH)D with iPTH suggests physiological relevance. Fetal vitamin D levels mirror maternal hypovitaminosis D, and fetal hypovitaminosis is common, assuming public health importance. On summarising hypovitaminosis D was common in both urban and rural subjects living in a tropical country. A significant correlation of 25(OH)D with iPTH suggests physiological relevance. Fetal vitamin D levels mirror maternal hypovitaminosis D, and fetal hypovitaminosis is common.

Summary... Vitamin D deficiency equally common among urban and rural subjects, despite rural subjects having better sun exposure Possible contributing factors Urban: low sun exposure Rural: low calcium intake Dark skin less efficient in making vitamin D? Possible contributory factors for hypovitaminosis D can be low sun exposure due to traditional clothing practices, avoidance of sun exposure and dark skin in urban subjects and low calcium intake for the rural subjects.

Future Directions Effect on neonatal calcium metabolism S. calcium iPTH

Thank You