[Iodine intake of two-year-olds and adults in Iceland and estimation of the effect of using iodized salt in breads].

INTRODUCTION: Insufficient iodine status was recently identified in pregnant women in Iceland. Iodine fortification of salt is widely used to decrease the risk of iodine deficiency disorders, but the use of iodized salt has not been recommended in Iceland. The aim was to describe iodine intake among Icelandic adults and two-year-olds and estimate the effect of using iodized salt in bread. MATERIAL AND METHODS: Iodine intake was assessed using data from the Icelandic National Dietary Survey 2019-2021 (18-80 years, n=822) and a study of two-year-old children (n=124). Data on bread intake was used to estimate expected iodine intake if iodized salt was used in bread. The results are compared with recommended iodine intake (90 µg/day for two-year-olds and 150 µg/day for adults) and upper intake level (200 µg/day and 600 µg/day, respectively). RESULTS: Average iodine intake was 88 µg/day for children and 134 µg/day for adults. If all types of bread consumed would contain 20 µg of iodine in 100 grams, the average iodine intake would increase to 99 and 153 µg/day, respectively. With higher bread iodine content, >5% of two-year-olds would exceed the upper intake level, while concentration up to 70 µg/100 grams of bread would result in iodine intake below the upper intake level for adults. CONCLUSION: Use of iodized salt in bread corresponding to 20µg of iodine in 100 grams of bread seems safe for young children in Iceland. However, based on the current dietary habits, adding this amount of iodine to bread would not be sufficient to secure optimal intake of iodine in all adults.

[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.

Lower Intake of Saturated Fatty Acids Is Associated with Improved Lipid Profile in a 6-Year-Old Nationally Representative Population.

To strengthen the organization of new national dietary surveys and interventions in childhood, our aim was to study macronutrient intake and blood lipid profile at 6 years of age by comparing results from two earlier population-based cohorts. Subjects were n = 131 and n = 162 in the years 2001−2002 and 2011−2012, respectively. Three-day weighed food records were used to estimate diet and calculate nutrient intake. Total cholesterol, HDL-cholesterol and triacylglycerol were measured in serum and LDL-cholesterol was calculated. The average intake of saturated fatty acids (SFA) and trans FA was lower in 2011−2012 than 2001−2002 (13.3E% vs. 14.7E%, p < 0.001, and 0.8E% vs. 1.4E%, p < 0.001, respectively), replaced by a higher intake of unsaturated fatty acids. Total cholesterol and LDL-cholesterol were significantly lower in 2011−2012 than 2001−2002 (4.6 vs. 4.4 mmol/L, p = 0.003 and 2.8 vs. 2.5 mmol/L, p < 0.001, respectively). In a multiple linear regression model, one E% increase in SFA intake was related to a 0.03 mmol/L increase in LDL cholesterol (p = 0.04). A lower intake of saturated and trans fatty acids, replaced by unsaturated fatty acids, may have contributed to an improved lipid profile in a healthy 6-year-old population. Biological data for analysis of blood lipids are important in national dietary surveys in healthy children to monitor important health outcomes of interventions.

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.

[Vitamin D status before and after metabolic and bariatric surgery at Landspitali].

INTRODUCTION: Long-term results from bariatric surgery amongst individuals with obesity is considered good in general, with regard to weight loss, complications of obesity or quality of life. However, risk of nutrient deficiency might be increased. The aim of the study was to assess vitamin D status of patients before and after metabolic and bariatric surgery at Landspitali. METHODS: Data on 25(OH)D concentration and parathyroid hormone (PTH) was retrieved from medical records for patients undergoing metabolic and bariatric surgery at Landspitali from 2001-2018 (n=539). Insufficient vitamin D status was defined as 25(OH)D concentration p<45 nmol/L in 2001-2012 but p<50 nnmol/L from 2013-2018, due to changes in analytical method during the study period. Vitamin D deficiency was defined as 25(OH)D p<30 nmol/L for both time periods. Guidelines on supplement use are provided before discharge from the hospital and up to 18 months after surgery, RESULTS: Mean concentration of 25(OH)D before surgery was 51 nmol/L (SD 30 nmol/L) and 278 (52%) had insufficient vitamin D status, of which quarter of subjects were defined as being vitamin D deficient. Concentration of 25(OH)D increased after surgery in majority of subjects (85%). However, about third of those defined as having insufficient vitamin D status before surgery still had insufficient status 18 months after surgery. When comparing time periods, 2001-2012 and 2013-2018 it can be seen that insufficient vitamin D status was less common in the second period, although still persistent in about 25% of cases before surgery and 8,5% 18 months after surgery. CONCLUSION: Insufficient vitamin D status is relatively common before metabolic and bariatric surgery at Landspitali. In large majority of subjects, 25(OH)D concentration increased after surgery, following recomendations on supplement intake. The results highlight the need for greater emphasis on correcting possible nutrient deficiencies before surgery.

Iodine status of breastfed infants and their mothers' breast milk iodine concentration.

Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother-infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother-infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast-milk energy content. The median (25th-75th percentiles) UIC was 152 (79-239) µg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 µg/day, based on urinary data (assuming an average urine volume of 300-500 ml/day and UIC from the present study). The median (25th-75th percentiles) BMIC was 84 (48-114) µg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants.

Insufficient iodine status in pregnant women as a consequence of dietary changes.

BACKGROUND: Historically, Iceland has been an iodine-sufficient nation due to notably high fish and milk consumption. Recent data suggest that the intake of these important dietary sources of iodine has decreased considerably. OBJECTIVE: To evaluate the iodine status of pregnant women in Iceland and to determine dietary factors associated with risk for deficiency. METHODS: Subjects were women (n = 983; 73% of the eligible sample) attending their first ultrasound appointment in gestational weeks 11-14 in the period October 2017-March 2018. Spot urine samples were collected for assessment of urinary iodine concentration (UIC) and creatinine. The ratio of iodine to creatinine (I/Cr) was calculated. Median UIC was compared with the optimal range of 150-249 µg/L defined by the World Health Organization (WHO). Diet was assessed using a semiquantitative food frequency questionnaire (FFQ), which provided information on main dietary sources of iodine in the population studied (dairy and fish). RESULTS: The median UIC (95% confidence interval (CI)) and I/Cr of the study population was 89 µg/L (42, 141) and 100 (94, 108) µg/g, respectively. UIC increased with higher frequency of dairy intake, ranging from median UIC of 55 (35, 79) µg/L for women consuming dairy products <1 time per week to 124 (98, 151) µg/L in the group consuming dairy >2 times per day (P for trend <0.001). A small group of women reporting complete avoidance of fish (n = 18) had UIC of 50 (21, 123) µg/L and significantly lower I/Cr compared with those who did not report avoidance of fish (58 (34, 134) µg/g vs. 100 (94, 108) µg/g, P = 0.041). Women taking supplements containing iodine (n = 34, 3.5%) had significantly higher UIC compared with those who did not take supplements (141 (77, 263) µg/L vs. 87 (82, 94), P = 0.037). CONCLUSION: For the first time, insufficient iodine status is being observed in an Icelandic population. There is an urgent need for a public health action aiming at improving iodine status of women of childbearing age in Iceland.

Effect of two different nutritional supplements on postprandial glucose response and energy- and protein intake in hospitalised patients with COPD: A randomised cross-over study.

INTRODUCTION: Oral nutrition support is frequently used in treatment of malnutrition in patients with chronic obstructive pulmonary disease (COPD). Considering the use of corticoidsteroids in patients with COPD, little is known about the effect on postprandial glucose response and if they might interfere with glucose control. Our aims were to compare the effect of a liquid oral nutritional supplement (ONS) and semi solid inbetween meal snack (snack) on postprandial glucose and energy- and protein intake, and to compare the effect of timing of each intervention on postprandial glucose and energy- and protein intake. METHODS: Patients with COPD (n = 17) admitted to the Department of Pulmonary Medicine, Iceland and defined as at low or medium nutritional risk (score 0-3) were recruited. In a randomised cross-over design, subjects consumed ONS or snack either in a fasting state (study 1) or following breakfast (study 2) and postprandial glucose responses were assessed at regular intervals for two hours (t = 15, t = 30, t = 45, t = 60, t = 90, t = 120 min). Energy- and protein intake was estimated using a validated plate diagram sheet. Wilcoxon Signed-Rank test was used to compare the two interventions. RESULTS: In study 2, following breakfast, postprandial glucose was significantly higher after consuming ONS than the snack after 60 min (9.7 ± 2.4 mmol/L vs. 8.2 ± 3.2 mmol/L, p = 0.013 and 120 min 9.2 ± 3.2 mmol/L vs. 7.9 ± 2.4 mmol/L, p = 0.021, respectively). No difference was found in postprandial glucose concentrations between ONS and the snack when consumed after overnight fasting (study 1). No difference in energy or protein intake from hospital food was seen between supplement types neither in study 1 or 2. CONCLUSION: Lower postprandial glucose concentrations were associated with the snack compared to ONS when taken after a meal compared to either type directly after overnight fasting. The clinical relevance of higher postprandial blood glucose after consuming a liquid ONS after breakfast compared with a semi solid snack needs to be studied further.

Infant Feeding, Vitamin D and IgE Sensitization to Food Allergens at 6 Years in a Longitudinal Icelandic Cohort.

Nordic Nutrition Recommendations (NNR) recommend exclusive breastfeeding until 6 months, partial breastfeeding until 1 year or longer and irrespective of breastfeeding, avoiding solid foods before 4 months. Strong evidence was found for benefits of breastfeeding regarding growth and infections but limited/inconclusive evidence regarding atopic disease and asthma. Vitamin D is of special interest in the Nordic diet. The aim of this prospective study was to compare infant feeding and vitamin D between immunoglobulin E (IgE) sensitized (n = 14) and non-sensitized (n = 130) children at 6 years. Information on diet and vitamin D supplement use were collected with dietary recall (<5 months), 1-d food records (5 and 6 months) and 3-d weighed food records (12 months and 6 years). Serum-specific IgE-antibodies against milk, egg, cod, wheat, soy and peanut (cut-off specific IgE ≥ 0.35 kUA/L) were measured at 6 years and serum 25-hydroxyvitamin D at 12 months and 6 years. At 4 months, 57% of IgE sensitized vs. 23% of non-sensitized children (p < 0.01) had received solid food. At 12 months, IgE sensitized children had a lower intake of vitamin D (median (25th, 75th percentiles): 3.9 µg/d (3.2, 7.2) vs. 8.1 µg/d (4.4, 12.3), p = 0.03) and at 6 years, fewer used vitamin D supplements regularly (23% vs. 56%, p = 0.03). Introduction of solid foods prior to 4 months increased the odds of IgE-sensitization, OR = 4.9 (95%, CI = 1.4-16.6) and vitamin D supplement at 6 years decreased the odds of IgE-sensitization, OR = 0.2 (95%, CI = 0.1-0.98), adjusting for maternal smoking. These observations support the NNR in their recommendation against introducing complementary solid foods before the age of 4 months. Furthermore, they support encouraging vitamin D intake for young children at northern latitudes.

Oral nutrition supplements and between-meal snacks for nutrition therapy in patients with COPD identified as at nutritional risk: a randomised feasibility trial.

Introduction: Intervention studies have mainly used oral nutritional supplements (ONS) for the management of patients with chronic obstructive pulmonary disease (COPD) identified as at nutritional risk. In this 12-month randomised feasibility trial, we assessed the (1) feasibility of the recruitment, retention and provision of two interventions: ONS and between-meal snacks (snacks) and (2) the potential impact of the provision of snacks and ONS on body weight and quality of life in patients with COPD. Methods: Hospitalised patients with COPD, at nutritional risk, were randomised to ONS (n=19) or snacks (n=15) providing 600 kcal and 22 g protein a day in addition to regular daily diet. The intervention started in hospital and was continued for 12 months after discharge from the hospital. Results: Study recruitment rate was n=34 (45%) and retention rate at 12 months was similar for both groups: n=13 (68%) in the ONS group and n=10 (67%) in the Snacks group. Both groups gained weight from baseline to 12 months (2.3±4.6 kg (p=0.060) in the ONS group and 4.4±6.4 kg (p=0.030) in the Snacks group). The St George's Respiratory Questionnaire total score improved from baseline to 12 months in both groups (score 3.9±11.0 (p=0.176) in the ONS group and score 8.9±14.1 (p=0.041) in the Snacks group). Discussion: In patients with COPD who are at nutritional risk snacks are at least as feasible and effective as ONS, however, adequately powered trials that take account of the difficulties in recruiting this patient group are required to confirm this effect.

Association of energy and protein intakes with length of stay, readmission and mortality in hospitalised patients with chronic obstructive pulmonary disease.

Low energy and protein intakes have been associated with an increased risk of malnutrition in outpatients with chronic obstructive pulmonary disease (COPD). We aimed to assess the energy and protein intakes of hospitalised COPD patients according to nutritional risk status and requirements, and the relative contribution from meals, snacks, drinks and oral nutritional supplements (ONS), and to examine whether either energy or protein intake predicts outcomes. Subjects were COPD patients (n 99) admitted to Landspitali University Hospital in 1 year (March 2015-March 2016). Patients were screened for nutritional risk using a validated screening tool, and energy and protein intake for 3 d, 1-5 d after admission to the hospital, was estimated using a validated plate diagram sheet. The percentage of patients reaching energy and protein intake ≥75 % of requirements was on average 59 and 37 %, respectively. Malnourished patients consumed less at mealtimes and more from ONS than lower-risk patients, resulting in no difference in total energy and protein intakes between groups. No clear associations between energy or protein intake and outcomes were found, although the association between energy intake, as percentage of requirement, and mortality at 12 months of follow-up was of borderline significance (OR 0·12; 95 % CI 0·01, 1·15; P=0·066). Energy and protein intakes during hospitalisation in the study population failed to meet requirements. Further studies are needed on how to increase energy and protein intakes during hospitalisation and after discharge and to assess whether higher intake in relation to requirement of hospitalised COPD patients results in better outcomes.

[Dietary intake of young Icelanders with psychotic disorders and weight development over an 8-12 months period].

INTRODUCTION: The prevalence of lifestyle related diseases is higher among people with psychotic disorders than the general population. The aim was to assess dietary intake of young people with psychotic disorders for the first time in Iceland. MATERIAL AND METHODS: Subjects were young people (n=48, age 18-30y) with psychotic disorders. Dietary intake was assessed by a 24-hour recall in July-August 2016, and compared with official recommendations and intake of the general public (n=250, age 18-30y). Body weight in the past eight to 12 months, was retrieved from medical records. RESULTS: Consumption of fruits, fish, dairy products, vegetable and fish oil was significantly lower among subjects when compared with the general public, while their soft drink and sweets consumption was higher (p<0.001). Furthermore, the contribution of added sugar was higher (15E% vs. 12E%) and protein intake lower (16E% vs. 18E%). Consumption of omega-3 fatty acids and vitamin D was lower among subjects than the general public and lower than recommended (0.04±0.3% omega-3 of total energy vs. 1.2±0.6%, p<0.001 and 3.1±4.2 µg vitamin D/day vs. 5.6±6.5 µg/day, p<0.001). Almost 40% of the subjects had gained >5% of their initial body weight in the past 8-2 months. CONCLUSION: Diet of young people with psychotic disorders is not consistent with recommendations and is worse than the diet of their peers in the general population. It is important to find ways to improve the diet and thereby nutrient intake of the group. Key words: psychotic disorders, schizophrenia, recommended dietary allowances, fatty acids, omega-3, vitamin D. Correspondence: Ingibjorg Gunnarsdottir, ingigun@landspitali.is.

Dietary supplement use in the older population of Iceland and association with mortality.

Dietary supplements are often used by the elderly to improve their nutritional status. However, intake above the recommended dietary levels may be detrimental, and uncertainty exists on the potential health benefits of supplementation in this population. The aim of this study was to describe supplement use among Icelandic older adults and to assess its association with total mortality and CVD-related mortality. This study used data from the Age Gene/Environment Susceptibility-Reykjavik study, which recruited 5764 participants aged 66-98 years in 2002-2006. Intake of vitamins and minerals from dietary supplements was estimated from interviews. Hazard ratios (HR) for mortality were estimated in multivariate analyses with follow-up ending in 2009. The results showed that most (77 %) of the participants used supplements. Overall, the consumption of vitamins and minerals from supplements was moderate although 22 and 14 % of users exceeded the upper recommended intake levels for vitamin B6 and Zn, respectively. Supplement users followed in general a healthier lifestyle than non-users. There were 1221 deaths including 525 CVD-related deaths during the follow-up period. When comparing multivitamin users with non-users in multivariable models, no associations with total mortality (HR 0·91; 95 % CI: 0·77, 1·08) or CVD-related mortality (HR 0·91; 95 % CI 0·70, 1·18) were observed. In conclusion, users of supplements generally lead healthier lifestyles than non-users and supplements did not confer any added advantage or harm relative to mortality risk. However, the intake of vitamin B6 and Zn from dietary supplements exceeded the recommended daily intake for almost a quarter of the supplement users.

[Diet and nutrient intake of pregnant women in the capital area in Iceland].

INTRODUCTION: Nutrition in pregnancy may affect growth, development and health of the child in the short and long term. We aimed to assess diet and nutrient intake among pregnant women in the capital area and evaluate differences in dietary intake between women who were overweight/obese and normal weight before pregnancy. MATERIAL AND METHODS: Pregnant women aged 18-40 years (n=183) living in the capital area kept four day weighed food records to assess diet and nutrient intake in the 19th-24th week of pregnancy (n=98 with body mass index (BMI) <25 kg/m2; n=46 with BMI 25-29.9 kg/m2 and n=39 with BMI ≥30 kg/m2). RESULTS: Only 20% of the women consumed the minimum recommended 25 g/day of dietary fibers. The contribution of added sugar to the total energy intake was on average 12% (SD ± 5%). About one-fourth appeared not to meet requirements for iodine, vitamin D and DHA (docosahexaenoic acid). No overconsumption of vitamins and minerals from food or supplements was observed. Higher median intake of milk and dairy products (346 g/day vs. 258 g/day, p<0.05), soft drinks (200 g/day vs. 122 g/day, p<0.05), as well as chips and popcorn (13 g/day vs. 0 g/day, p<0,05) was observed among women with BMI ≥30 kg/m2 compared with women of normal weight before pregnancy (BMI <25 kg/m2). CONCLUSION: Dietary habits and choices among women require enhanced consideration both before and in pregnancy, particularly among those who are obese. Sub-optimal consumption of iodine, vitamin D and DHA, was seen among up to a quarter of the pregnant women. KEY WORDS: pregnancy, nutrition, dietary intake, essential fatty acids, iodine, vitamin D, folic acid. Correspondence: Ingibjorg Gunnarsdottir, ingigun@hi.is.

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.

Cod liver oil consumption at different periods of life and bone mineral density in old age.

Cod liver oil is a traditional source of vitamin D in Iceland, and regular intake is recommended partly for the sake of bone health. However, the association between lifelong consumption of cod liver oil and bone mineral density (BMD) in old age is unclear. The present study attempted to assess the associations between intake of cod liver oil in adolescence, midlife, and old age, and hip BMD in old age, as well as associations between cod liver oil intake in old age and serum 25-hydroxyvitamin D (25(OH)D) concentration. Participants of the Age, Gene/Environment Susceptibility-Reykjavik Study (age 66-96 years; n 4798), reported retrospectively cod liver oil intake during adolescence and midlife, as well as the one now in old age, using a validated FFQ. BMD of femoral neck and trochanteric region was measured by volumetric quantitative computed tomography, and serum 25(OH)D concentration was measured by means of a direct, competitive chemiluminescence immunoassay. Associations were assessed using linear regression models. No significant association was seen between retrospective cod liver oil intake and hip BMD in old age. Current intake of aged men was also not associated with hip BMD, while aged women with daily intakes had z-scores on average 0.1 higher, compared with those with an intake of < once/week. Although significant, this difference is small, and its clinical relevance is questionable. Intake of aged participants was positively associated with serum 25(OH)D: individuals with intakes of < once/week, one to six time(s)/week and daily intake had concentrations of approximately 40, 50 and 60 nmol/l respectively (P for trend < 0.001).

Vitamin D intake and status in 12-month-old infants at 63-66° N.

The objective was to assess the vitamin D status in healthy 12-month-old infants in relation to quantity and sources of dietary vitamin D, breastfeeding and seasons. Subjects were 76 12-month-old infants. Serum levels of 25-hydroxyvitamin D (25(OH)D) ≥ 50 nmol/L were considered indicative of vitamin D sufficiency and 25(OH)D < 27.5 nmol/L as being indicative of increased risk for rickets. Additionally, 25(OH)D > 125 nmol/L was considered possibly adversely high. Total vitamin D at 9-12 months (eight data collection days) included intake from diet and supplements. The mean ± SD of vitamin D intake was 8.8 ± 5.2 µg/day and serum 25(OH)D 98.1 ± 32.2 nmol/L (range 39.3-165.5). Ninety-two percent of infants were vitamin D sufficient and none at increased risk for rickets. The 26% infants using fortified products and supplements never/irregularly or in small amounts had lower 25(OH)D (76.8 ± 27.1 nmol/L) than the 22% using fortified products (100.0 ± 31.4 nmol/L), 18% using supplements (104.6 ± 37.0 nmol/L) and 33% using both (110.3 ± 26.6 nmol/L). Five of six infants with 25(OH)D < 50 nmol/L had no intake of supplements or fortified products from 0 to 12 months. Supplement use increased the odds of 25(OH)D > 125 nmol/L. Breastfeeding and season did not affect vitamin D status. The majority of infants were vitamin D sufficient. Our findings highlight the need for vitamin D supplements or fortified products all year round, regardless of breastfeeding.

Effects of a healthy Nordic diet on plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome: a randomized, [corrected] controlled trial (SYSDIET).

PURPOSE: At northern latitudes, vitamin D is not synthesized endogenously during winter, causing low plasma 25-hydroxyvitamin D (25(OH)D) concentrations. Therefore, we evaluated the effects of a healthy Nordic diet based on Nordic nutrition recommendations (NNR) on plasma 25(OH)D and explored its dietary predictors. METHODS: In a Nordic multi-centre trial, subjects (n = 213) with metabolic syndrome were randomized to a control or a healthy Nordic diet favouring fish (≥300 g/week, including ≥200 g/week fatty fish), whole-grain products, berries, fruits, vegetables, rapeseed oil and low-fat dairy products. Plasma 25(OH)D and parathyroid hormone were analysed before and after 18- to 24-week intervention. RESULTS: At baseline, 45 % had vitamin D inadequacy (<50 nmol/l), whereas 8 % had deficiency (<25 nmol/l). Dietary vitamin D intake was increased by the healthy Nordic diet (P < 0.001). The healthy Nordic and the control diet reduced the prevalence of vitamin D inadequacy by 42 % (P < 0.001) and 19 % (P = 0.002), respectively, without between-group difference (P = 0.142). Compared with control, plasma 25(OH)D (P = 0.208) and parathyroid hormone (P = 0.207) were not altered by the healthy Nordic diet. Predictors for 25(OH)D were intake of vitamin D, eicosapentaenoic acids (EPA), docosahexaenoic acids (DHA), vitamin D supplement, plasma EPA and plasma DHA. Nevertheless, only vitamin D intake and season predicted the 25(OH)D changes. CONCLUSION: Consuming a healthy Nordic diet based on NNR increased vitamin D intake but not plasma 25(OH)D concentration. The reason why fish consumption did not improve vitamin D status might be that many fish are farmed and might contain little vitamin D or that frying fish may result in vitamin D extraction. Additional ways to improve vitamin D status in Nordic countries may be needed.

Iodine status of pregnant women in a population changing from high to lower fish and milk consumption.

OBJECTIVES: Pregnancy is one of the most critical periods for iodine deficiency. The aim of the present study was to assess the iodine status and dietary intake of pregnant women in a population changing from high to lower consumption of milk and fish. DESIGN: Cross-sectional observational study. Urine samples were collected for measuring urinary iodine concentration (UIC) and creatinine, and blood samples for measuring serum thyroid-stimulating hormone (TSH). Frequency of consumption of selected food and beverages was obtained through a semi-quantitative validated FFQ. The difference in the distribution of UIC, ratio of iodine to creatinine (I:Cr) and TSH between groups following recommendations on fish and dairy product intake or not (fish ≥2 times/week as a main meal, diary products ≥2 portions/d) was assessed. SETTING: Primary Health Care of the Capital Area, Reykjavik, Iceland. SUBJECTS: Randomly selected pregnant women (19-43 years old, n 162). RESULTS: The median UIC was 180 µg/l, I:Cr 173 µg/g and TSH 1·5 mmol/l. Women who did not consume fish ≥2 times/week and also did not consume dairy products in line with the recommended intake level of ≥2 portions/d had median UIC of 160 µg/l (I:Cr 149 µg/g) compared with 220 µg/l (I:Cr 190 µg/g) in the group following both the recommendations for fish and those for dairy products. Use of dietary supplements in the two groups was similar. CONCLUSIONS: Iodine status in the population studied was within the optimal range (150-249 µg/d) defined by the WHO.

Iodine intake in human nutrition: a systematic literature review.

The present literature review is a part of the NNR5 project with the aim of reviewing and updating the scientific basis of the 4th edition of the Nordic Nutrition Recommendations (NNR) issued in 2004. The main objective of the review is to assess the influence of different intakes of iodine at different life stages (infants, children, adolescents, adults, elderly, and during pregnancy and lactation) in order to estimate the requirement for adequate growth, development, and maintenance of health. The literature search resulted in 1,504 abstracts. Out of those, 168 papers were identified as potentially relevant. Full paper selection resulted in 40 papers that were quality assessed (A, B, or C). The grade of evidence was classified as convincing, probable, suggestive, and no conclusion. We found suggestive evidence for improved maternal iodine status and thyroid function by iodine supplementation during pregnancy. Suggestive evidence was found for the relationship between improved thyroid function (used as an indicator of iodine status) during pregnancy and cognitive function in the offspring up to 18 months of age. Moderately to severely iodine-deficient children will probably benefit from iodine supplementation or improved iodine status in order to improve their cognitive function, while only one study showed improved cognitive function following iodine supplementation in children from a mildly iodine-deficient area (no conclusion). No conclusions can be drawn related to other outcomes included in our review. There are no new data supporting changes in dietary reference values for children or adults. The rationale for increasing the dietary reference values for pregnant and lactating women in the NNR5 needs to be discussed in a broader perspective, taking iodine status of pregnant women in the Nordic countries into account.