Endocrine, Metabolic & Immune Disorders -Drug Targets Vasiliki Sideri 1 , George Antonakos 2 , Andreas Fretzayas 1 , Achilleas Attilakos 1 , Charalambos Chrelias 3 , Vasiliki Papaevangelou 1 , Polyxeni Nicolaidou 1 and Anna Papadopoulou 1,* 1 3 rd Department of Paediatrics, National and Kapodistrian University of Athens, “Attikon” University General Hospital, Athens, Greece; 2 Laboratory of Clinical Biochemistry, “Attikon” University General Hospital, Athens, Greece; 3 3 rd Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens, “Attikon” University General Hospital, Athens, Greece  A R T I C L E H I S T O R Y Received: March 13, 2018 Revised: May 31, 2018 Accepted: June 27, 2018 DOI: 10.2174/1871530318666180723103117 Abstract: Background/Objectives: The aim of this work was to evaluate the current vitamin D status in healthy pregnant women and their newborns living in Greece and assess possible associations be- tween 25(OH)D and anthropometric features of their fetuses and newborns. Materials & Methods: 81 healthy women were monitored during pregnancy. Biochemical markers related to bone metabolism, 25(OH)D and PTH levels were measured in serum samples of mother- newborn pairs at 1st trimester of pregnancy and at delivery in mothers, in cord blood and at the 3 rd day of life of newborns. Results: Maternal 25(OH)D levels at the 1st trimester of pregnancy (22.6±9.2ng/ml) were significantly higher than those at delivery (19.2±9.2ng/ml) (p<0.001). Furthermore, umbilical 25(OH)D levels (21.3±9.3ng/ml) were higher than maternal at delivery (p=0.005) and neonatal levels (19.4±10.4 ng/ml) (p=0.021). Only 57.3% of the mothers at the first trimester and 46.7% at delivery as well as 55.8% of the fetuses and 38.5% of the neonates had adequate vitamin D levels (25(OH)D≥30ng/ml). A significant positive correlation was found between fetal femur length at the 22nd week of gestation and maternal 25(ΟΗ)D at the 1st trimester of pregnancy (r=0.36, p=0.048) while body length was signifi- cantly higher in newborns whose mothers had sufficient 25(OH)D levels (51.5±2.1cm) compared with those whose mothers had insufficient or deficient 25(OH)D levels at delivery (50.6±2.0cm) (p=0.047). Conclusion: The study confirms inadequate levels of vitamin D in pregnant women in Greece associ- ated with inadequate vitamin D levels of their fetuses and newborns. Keywords: Vitamin D deficiency/insufficiency, pregnancy, fetus, newborn, PTH levels, hypovitaminosis. 1. INTRODUCTION The implication of vitamin D in multiple biological cir- cuits such as immunomodulation, cellular proliferation and differentiation led to extensive research regarding the deter- mination of the optimal serum levels and the clinical conse- quences of low or high blood concentrations [1, 2]. Serum vitamin D levels are mainly expressed by 25(OH)D which constitutes the human reservoir of vitamin D due to its long half-time life (2-3weeks) [1, 3] and subsequently determines the deficient, insufficient or sufficient vitamin D status. Given that vitamin D is found naturally only in a few foods, such as egg yolk, salmon, and liver, maternal 25(OH)D lev- els depend basically on the amount of sunlight exposure and *Address correspondence to this author at the Biochemist-Molecular Biolo- gist, 3 rd Department of Pediatrics, National and Kapodistrian University of Athens, “Attikon” University General Hospital, 1, Rimini Str, 12462 Ath- ens, Greece; Tel: +302105832228; Fax: +302105832229; E-mail: anpa- pado@med.uoa.gr on vitamin D supplementation [1]. Furthermore, the amount of UV exposure available for the cutaneous synthesis of vi- tamin D depends on several parameters such as the time spent outdoors, skin pigmentation, body mass index, clothing habits, the latitude of a region, the use of sunscreens, the season of the year and air pollution [1]. Hypovitaminosis D has been reported by a significant number of epidemiological and observational studies in vari- ous physiological and pathological conditions in human life, in different geographic regions and different cultures [2, 4]. However, it should be noticed that besides the emerging data, an inconclusive debate is still in progress regarding vitamin D normal ranges. Based on clinical observations on bone health and laboratory measurements of bone markers, research groups and organizations publish guidelines for 25(OH)D ranges and vitamin D supplementation. In particu- lar, the Endocrine Society, defines as deficient, insufficient and sufficient vitamin D status 25(OH)D serum levels less than 20ng/ml (<50nmol/L); 21-29 ng/ml (52,5-75nmol/L) 2212-3873/19 $58.00+.00 © 2019 Bentham Science Publishers Send Orders for Reprints to reprints@benthamscience.ae Endocrine, Metabolic & Immune Disorders - Drug Targets, 2019, 19, 159-165 159 RESEARCH ARTICLE Hypovitaminosis D in Healthy Pregnant Women and their Newborns in Greece