Association of low intake of milk and vitamin D during pregnancy with decreased birth weight

Abstract

ResearchM ilk is an important source of vitamin D, calcium, riboflavin, protein and energy during pregnancy, yet many women choose or are advised to avoid drinking milk for a variety of reasons, including the prevention of allergies in their children.1 Limiting milk intake compromises the quality of the maternal diet; 2-5 women who avoid milk may not obtain adequate levels of vitamin D, calcium, protein or riboflavin. Milk restriction is a risk factor for pregnancy-associated hypertension.6 Low vitamin D intake is associated with neonatal rickets 7 and decreased birth weight. 8Inadequate consumption of riboflavin is associated with decreases in weight, 9 length and head circumference of babies at birth. 10Although most nutrients in milk may be replaced from other foods or with supplements, vitamin D is found in few commonly consumed foods except for milk fortified with the vitamin.11 Dermal conversion of the precursor cholecalciferol to activated vitamin D is a seasonally unreliable source, particularly when the exposure of skin to sunlight is limited, 12and may not compensate for low nutritional intake. Under optimal conditions, 15 minutes of daily exposure of the hands and face to sun is required to produce adequate vitamin D, 13 but this conversion is reduced by the prolonged winter season at more polar latitudes, 14,15 by use of sunscreens with a sun protection factor (SPF) above 8, 16 and by ozone air pollution. 13People whose skin pigmentation is dark are more vulnerable than others to insufficient vitamin D conversion. 16In this study we compared the birth weight, crown-heel length and head circumference of newborns whose mothers restricted their intake of milk during pregnancy with the babies of those who did not. MethodsBetween May 1997 and June 1999 we screened 2091 women who attended prenatal classes at 3 hospitals in Calgary, Alberta. The study was approved by the Institutional Review Board of McGill University as well as by the Calgary Health Region Ethics Board.Women were given an anonymous questionnaire that asked whether they would be willing to participate in an indepth study on dietary intake and pregnancy outcomes, and if they restricted dairy products for any reason. For consenting participants, a second questionnaire asked for demographic data, lifestyle characteristics (e.g., smoking habits, highest level of education achieved) and if they had certain metabolic conditions (e.g., diabetes, hypertension) or a multiple pregnancy. Only healthy mothers with singleton pregnancies were Association of low intake of milk and vitamin D during pregnancy with decreased birth weightB Ba ac ck kg gr ro ou un nd d: : Some pregnant women may be advised or choose to restrict milk consumption and may not take appropriate supplements. We hypothesized that maternal milk restriction during pregnancy, which can reduce intakes of protein, calcium, riboflavin and vitamin D, might represent a health risk by lowering infant birth weight. M Me et th ho od ds s: : We screened women between the ages of 19 and 45 years...

Vitamin D and assisted reproduction: should vitamin D be routinely screened and repleted prior to ART? A systematic review

“…This study reported a decrease in the inflammatory response with vitamin D treatment by measurement of IL-8 [24]. Also of note, vitamin D has been associated with increased risk of preeclampsia [25], infants that are small for gestational age (SGA) [26][27][28][29], cesarean section [30], and gestational diabetes (GDM) [31].…”

The association of maternal diet and dietary supplement intake in pregnant New Zealand women with infant birthweight

“…Few foods are supplemented with vitamin D in New Zealand. Mannion et al (2006) found that intake of milk fortified with vitamin D, and intake of vitamin D were each positively associated with birthweight. Olsen et al (2007) also found that milk and milk protein intake was associated with higher birthweight and suggested that water soluble substances in milk increase fetal growth.…”

Association of Milk and Dairy Products Consumption During Pregnancy with Fetal and Neonatal Head Circumferences: A Systematic Review

“…Mannion et al (12) reported that neonatal birth head circumference in females, who consumed ≤ 250 mL/d of milk in comparison with higher consumption were similar. In addition, Borazjani (13) found no association between maternal milk consumption during pregnancy and neonatal birth head circumference.…”

“…Among the seven studies, four studies reported results of maternal milk or dairy products consumption in relation to neonatal birth head circumference (12,14,15,17), one study reported results of maternal milk or dairy products consumption in relation to fetal head circumference (18) and two studies reported results of maternal milk or dairy products consumption in relation to both fetal and neonatal birth head circumferences (13,16).…”

“…One cohort study, one cross-sectional study and one randomized controlled trial (12)(13)(14) showed that maternal milk or dairy products consumption was not associated with neonatal birth head circumference, while three cohort studies (15)(16)(17) reported that maternal milk or dairy products intake had a positive effect on neonatal birth head circumference.…”