Vitamin D intake of pregnant women in the Borders
(2015) Vitamin D intake of pregnant women in the Borders, no. 25.
Introduction: It is well established in literature and reflected in recommendations that vitamin D plays an essential role in bone development and prevention of deficiency related diseases such as rickets. Recent research suggests that vitamin D also plays a role in muscle development, skeletal muscle fibre proliferation, prevention of atopic disease development and reduction in depressive symptoms in mothers postpartum. It is known that vitamin D in pregnancy is essential for pre and postnatal development but the current intakes of pregnant women in the UK are unknown. As pregnancy is a time of vulnerability for nutrient deficiency - due to changes in diet and lifestyle - this study aims to 1) analyse the dietary intakes of vitamin D in pregnant women in the Scottish Borders, 2) determine the contribution of supplements to overall vitamin D intake and 3) compare intakes with Reference Nutrient Intakes and demographic differences within the sample. Methods: Pregnant women were recruited from privately run antenatal classes in the Borders. Their dietary intake of vitamin D was estimated by the use of a Food Frequency Questionnaire specifically adapted to include vitamin D rich food sources and suit differences in diet during pregnancy. In addition diet, supplement use was estimated by an additional section in the questionnaire followed by a general information section requesting information on age, stage of pregnancy, number of previous pregnancies and postcode. Pearson's correlation coefficient was used to assess the direction and strength of linear relationships between vitamin D and the previously mentioned participant demographics. An Independent T-test was conducted to compare intakes between those in different deprivation quintiles (3 and 4) and those at different stages of pregnancy (second or third trimester). A One-Way Analysis of Variance was conducted to identify any differences in intake between those on their first pregnancy or those who had been pregnant before once or twice before. Results: Eleven pregnant women with a mean±sd age of 32.9±4.25 years were recruited and completed this study. As categorized by the SIMD, five participants lived in areas ranked as deprivation quintile 3, five lived in quintile 4 and one lived in quintile 5. Seven participants were in their first pregnancy, 2 had been pregnant once before and 2 had been pregnant twice before. There were no participants in the first trimester - 5 were in the second trimester and 6 were in the third. No medical conditions that may affect intake were declared. Intake was not found to be affected by age, stage of pregnancy or deprivation quintile. A strong positive association (r=0.496) was found between intake and previous pregnancies. Dietary intakes of vitamin D were estimated at 2.73±1.75ug/d - when combined with supplementary vitamin D (the most common form of which was a multivitamin) intakes were estimated at 15.45±8.26ug/d, therefore, 10 out of 11 participants met the RNI of 10ug/d. Conclusion: It can be assumed that middleclass pregnant women in the Borders are meeting the recommendations for vitamin D intake - particularly those who have been pregnant before. By doing so these women are reducing their child's risk of deficiency related illnesses such as rickets and atopic diseases as well as ensuring proper development of muscles. In terms of maternal health, they are protecting themselves from similar deficiency related illness as well as depressive symptoms post partum. As multivitamins were the most common form of supplement it is likely these women are also meeting other important nutrient recommendations - this study confirmed this for calcium and folate and further dietary analysis could be done to assess others. If observed as a pilot, this study provides an effective method and framework for future research on vitamin D or other important nutrients and could be rolled out on a wider scale with a sample more representative of the extremes of deprivation and all stages of pregnancy. Key words: Pregnancy, vitamin D, foetal development, muscle development, bone development