Skeletal Development In Utero With Vitamin D Deficiency
Vitamin D Insufficiency and Skeletal Development In Utero
Martin Hewison and John S Adams
UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, David Geffen School of Medicine, UCLA, Los Angeles, CA, USAAbstract:
Over the last 10 years, our perception of what constitutes
normal vitamin D status has undergone a substantial
revision. Prior to this, suboptimal vitamin D was defined at a very
basic level by the presence or absence of associated bone
disease (i.e., rickets in children and osteomalacia in adults). As a
consequence, vitamin D deficiency was determined by serum
concentrations of 25-hydroxyvitamin D (25-OHD) of less than 25
nM (10 ng/mL), and anything higher was ‘‘normal.’’ However, this
has changed with the observation that several parameters of
calcium homeostasis continue to correlate with serum levels of
25-OHD up to concentrations as high as approximately 80 nM (32
ng/mL).(1,2) The implication is that optimal vitamin D status is
achieved only at 25-OHD concentrations above this; anything
less is suboptimal or ‘‘insufficient.’’ Based on these revised
parameters, it has been concluded that vitamin D insufficiency is
a global phenomenon, with an estimated 1 billion people
worldwide having suboptimal levels of 25-OHD.(3) Some groups
appear to be at greater risk of vitamin D insufficiency than others,
notably pregnant women.(4–8) In a study carried out in
Pittsburgh, PA, Bodnar and colleagues showed that 74% to
95% of pregnant black women and 46% to 62% of pregnant
white women were vitamin D insufficient.(5) Notably, during early
pregnancy, almost 45% of the African-American mothers had 25-
OHD levels that were less than 37.5 nM.(5) A key question arising
from these epidemiologic data concerns the physiologic impact
of vitamin D insufficiency during pregnancy. In the current issue
of the Journal, Mahon and colleagues have addressed this
through a prospective longitudinal study of pregnant women in
which they have characterized the impact of maternal vitamin D
status on in utero measures of fetal skeletal development.(9)
Source:
http://www3.interscience.wiley.com/cgi-bin/fulltext/123241992/PDFSTART
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