[Correlation between intake of fish or supplements containing omega-3 fatty acids and early pregnancy plasma concentrations.]

INTRODUCTION: Long-chain polyunsaturated omega-3 fatty acids are considered important for fetal development, but previous studies suggest suboptimal intake in part of pregnant women in Iceland. The study aim was to evaluate intake of food and supplements containing omega-3 fatty acids, among pregnant women in Iceland and correlations to fatty acid composition in plasma. MATERIALS AND METHODS: Subjects were 853 pregnant women attending their 11-14 weeks ultrasound appointment. Information on intake of food and supplements containing long-chain omega-3 fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) as well as background was obtained by a questionnaire. Blood samples were collected for analysis of plasma fatty acids. Correlation was evaluated using the Spearman correlation. RESULTS: Median intake of lean fish was 1.3 times per week, while fatty fish was consumed once monthly. About 50% of the women took omega-3 containing supplements daily. Higher intake of both fish and omega-3 containing supplements was reflected in higher omega-3 plasma levels (r=0.37 p<0.001). A positive correlation was seen between intake of cod liver oil/capsules (r=0.23, p=0.001), omega-3 oil/capsules (r=0.20, p=0.001) and plasma concentration of omega-3. However, no correlation was seen between intake of a maternal multivitamin containing omega-3 and corresponding plasma concentration (r=0.03, p=0.98). CONCLUSION: Intake of food and supplements containing omega-3 fatty acids was reflected in plasma concentration, except for an Icelandic maternal multivitamin. One third of the women followed the recommendation of eating fish at least twice weekly. About 50% had a daily intake of supplements containing omega-3 fatty acids.

Vitamin D status and association with gestational diabetes mellitus in a pregnant cohort in Iceland.

BACKGROUND: Vitamin D deficiency has been associated with an increased risk of gestational diabetes mellitus (GDM), one of the most common pregnancy complications. The vitamin D status has never previously been studied in pregnant women in Iceland. OBJECTIVE: The aim of this research study was to evaluate the vitamin D status of an Icelandic cohort of pregnant women and the association between the vitamin D status and the GDM incidence. DESIGN: Subjects included pregnant women (n = 938) who attended their first ultrasound appointment, during gestational weeks 11-14, between October 2017 and March 2018. The use of supplements containing vitamin D over the previous 3 months, height, pre-pregnancy weight, and social status were assessed using a questionnaire, and blood samples were drawn for analyzing the serum 25­hydroxyvitamin D (25OHD) concentration. Information regarding the incidence of GDM later in pregnancy was collected from medical records. RESULTS: The mean ± standard deviation of the serum 25OHD (S-25OHD) concentration in this cohort was 63±24 nmol/L. The proportion of women with an S-25OHD concentration of ≥ 50 nmol/L (which is considered adequate) was 70%, whereas 25% had concentrations between 30 and 49.9 nmol/L (insufficient) and 5% had concentrations < 30 nmol/L (deficient). The majority of women (n = 766, 82%) used supplements containing vitamin D on a daily basis. A gradual decrease in the proportion of women diagnosed with GDM was reported with increasing S-25OHD concentrations, going from 17.8% in the group with S-25OHD concentrations < 30 nmol/L to 12.8% in the group with S-25OHD concentrations ≥75 nmol/L; however, the association was not significant (P for trend = 0.11). CONCLUSION: Approximately one-third of this cohort had S-25OHD concentrations below adequate levels (< 50 nmol/L) during the first trimester of pregnancy, which may suggest that necessary action must be taken to increase their vitamin D levels. No clear association was observed between the vitamin D status and GDM in this study.

Old Question Revisited: Are High-Protein Diets Safe in Pregnancy?

BACKGROUND: A previous randomized dietary intervention in pregnant women from the 1970s, the Harlem Trial, reported retarded fetal growth and excesses of very early preterm births and neonatal deaths among those receiving high-protein supplementation. Due to ethical challenges, these findings have not been addressed in intervention settings. Exploring these findings in an observational setting requires large statistical power due to the low prevalence of these outcomes. The aim of this study was to investigate if the findings on high protein intake could be replicated in an observational setting by combining data from two large birth cohorts. METHODS: Individual participant data on singleton pregnancies from the Danish National Birth Cohort (DNBC) (n = 60,141) and the Norwegian Mother, Father and Child Cohort Study (MoBa) (n = 66,302) were merged after a thorough harmonization process. Diet was recorded in mid-pregnancy and information on birth outcomes was extracted from national birth registries. RESULTS: The prevalence of preterm delivery, low birth weight and fetal and neonatal deaths was 4.77%, 2.93%, 0.28% and 0.17%, respectively. Mean protein intake (standard deviation) was 89 g/day (23). Overall high protein intake (>100 g/day) was neither associated with low birth weight nor fetal or neonatal death. Mean birth weight was essentially unchanged at high protein intakes. A modest increased risk of preterm delivery [odds ratio (OR): 1.10 (95% confidence interval (CI): 1.01, 1.19)] was observed for high (>100 g/day) compared to moderate protein intake (80-90 g/day). This estimate was driven by late preterm deliveries (weeks 34 to <37) and greater risk was not observed at more extreme intakes. Very low (<60 g/day) compared to moderate protein intake was associated with higher risk of having low-birth weight infants [OR: 1.59 (95%CI: 1.25, 2.03)]. CONCLUSIONS: High protein intake was weakly associated with preterm delivery. Contrary to the results from the Harlem Trial, no indications of deleterious effects on fetal growth or perinatal mortality were observed.

Towards an Individualized Nutrition Treatment: Role of the Gastrointestinal Microbiome in the Interplay Between Diet and Obesity.

PURPOSE OF REVIEW: Dietary treatments for obesity have relatively low long-term success. Recent studies have identified the gastrointestinal microbiome as a factor of high relevance. The current knowledge on the interplay between diet, obesity, and the gastrointestinal microbiome and the potential for individualized dietary treatment will be discussed. RECENT FINDINGS: Studies indicate that each individual digests and metabolizes identical food substances differently depending on their gastrointestinal microbiome composition. Factors related to this crosstalk may improve our understanding of weight homeostasis and treatment of obesity. Long-time dietary intake is the key in the composition of the gastrointestinal microbiome which seems to be an important factor for energy balance, resulting in emerging opportunities for increasingly varied obesity treatment. Compliance to dietary treatment is critical for long-term success as enduring changes in gastrointestinal microbiome seem to slow over time. More research is urgently needed to investigate this missing link in our understanding of obesity.

Dietary habits in adolescence and midlife and risk of breast cancer in older women.

Recent studies indicate that lifestyle factors in early life affect breast cancer risk. We therefore explored the association of high consumption of meat, milk, and whole grain products in adolescence and midlife, on breast cancer risk. We used data from the population based AGES-Reykjavik cohort (2002-2006), where 3,326 women with a mean age of 77 years (SD 6.0) participated. For food items and principal component derived dietary patterns we used Cox proportional models to calculate multivariate hazard ratios (HR) with 95% confidence intervals (95% CI). During a mean follow-up of 8.8 years, 97 women were diagnosed with breast cancer. For both adolescence and midlife, daily consumption of rye bread was positively associated with breast cancer (HR 1.7, 95% CI 1.1-2.6 and HR 1.8, 95% CI 1.1-2.9, respectively). In contrast, persistent high consumption of oatmeal was negatively associated with breast cancer (0.4, 95% CI 0.2-0.9). No association was found for other food items or dietary patterns that included rye bread. High rye bread consumption in adolescence and midlife may increase risk of late-life breast cancer whilst persistent consumption of oatmeal may reduce the risk.

Vitamin D Intake and Status in 6-Year-Old Icelandic Children Followed up from Infancy.

High serum 25-hydroxyvitamin D (25(OH)D) levels have been observed in infants in Nordic countries, likely due to vitamin D supplement use. Internationally, little is known about tracking vitamin D status from infancy to childhood. Following up 1-year-old infants in our national longitudinal cohort, our aims were to study vitamin D intake and status in healthy 6-year-old Icelandic children (n = 139) and to track vitamin D status from one year of age. At six years, the mean 25(OH)D level was 56.5 nmol/L (SD 17.9) and 64% of children were vitamin D sufficient (25(OH)D ≥ 50 nmol/L). A logistic regression model adjusted for gender and breastfeeding showed that higher total vitamin D intake (Odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.08-1.49), blood samples collected in summer (OR = 8.88, 95% CI = 1.83-43.23) or autumn (OR = 5.64, 95% CI = 1.16-27.32) compared to winter/spring, and 25(OH)D at age one (OR = 1.02, 95% CI = 1.002-1.04) were independently associated with vitamin D sufficiency at age six. The correlation between 25(OH)D at age one and six was 0.34 (p = 0.003). Our findings suggest that vitamin D status in infancy, current vitamin D intake and season are predictors of vitamin D status in early school age children. Our finding of vitamin D status tracking from infancy to childhood provides motivation for further studies on tracking and its clinical significance.

Fish liver and seagull eggs, vitamin D-rich foods with a shadow: results from the Norwegian Fish and Game Study.

SCOPE: Fish liver, fish liver oil, oily fish and seagull eggs have been major sources of vitamin D for the coastal population of Norway. They also provide dioxin and polychlorinated dioxin-like compounds (dl-compounds), which may interfere with vitamin D homeostasis. We investigated whether serum 25-hydroxyvitamin D (25(OH)D) might be compromised by concomitant intake of dl-compounds. METHODS AND RESULTS: We studied 182 adults participating in the Norwegian Fish and Game Study. Participants who consumed fish liver and/or seagull eggs had higher dl-compound intake and blood concentrations than non-consumers (p < 0.001). Vitamin D intake was higher (p < 0.001), whereas serum 25(OH)D was lower (p = 0.029) in consumers than in non-consumers. Among non-consumers, vitamin D intake was associated with serum 25(OH)D (ß=1.06; 95% CI: 0.48, 1.63). This association was weaker among consumers (ß = 0.52; 95% CI: -0.05, 1.08), but strengthened when adjusted for retinol intake (ß = 0.66; 95% CI: 0.12, 1.21). The association between vitamin D intake and serum 25(OH)D did not seem to be compromised by intake of dl-compounds. CONCLUSION: To secure adequate vitamin D status while keeping the intake of dioxins and dl-polychlorinated biphenyls low, a healthy diet should include both supplemental vitamin D and oily fish. Despite high nutrient content, dietary fish liver and seagull eggs should be restricted, due to dl-compounds and possible vitamin A-D antagonism.