Browsing by Subject "D DEFICIENCY"

Sort by: Order: Results:

Now showing items 1-20 of 21
  • Rosendahl, Jenni; Fogelholm, Mikael; Pelkonen, Anna; Makela, Mika J.; Makitie, Outi; Erkkola, Maijaliisa (2017)
    Background/Aims: Vitamin D insufficiency is common in children. We aimed to evaluate the main determinants of vitamin D status in Finnish school-aged children, including the history of allergic diseases. Methods: We conducted a cross-sectional study on 171 ten-year-olds where serum 25-hydroxyvitamin D (25[OH] D) levels were measured, and data on food consumption and use of vitamin D supplements were collected. The history of allergic diseases was evaluated with a validated questionnaire. Results: Vitamin D insufficiency (
  • Einarsdottir, Elisabet; Pekkinen, Minna; Krjutskov, Kaarel; Katayama, Shintaro; Kere, Juha; Mäkitie, Outi; Viljakainen, Heli (2019)
    Objective: The effect of vitamin D at the transcriptome level is poorly understood, and furthermore, it is unclear if it differs between obese and normal-weight subjects. The objective of the study was to explore the transcriptome effects of vitamin D supplementation. Design and methods: We analysed peripheral blood gene expression using GlobinLock oligonucleotides followed by RNA sequencing in individuals participating in a 12-week randomised double-blinded placebo-controlled vitamin D intervention study. The study involved 18 obese and 18 normal-weight subjects (of which 20 males) with mean (+/- s.D.) age 20.4 (+/- 2.5) years and BMIs 36 (+/- 10) and 23 (+/- 4) kg/m(2), respectively. The supplemental daily vitamin D dose was 50 mu g (2000 IU). Data were available at baseline, 6- and 12-week time points and comparisons were performed between the vitamin D and placebo groups separately in obese and normal-weight subjects. Results: Significant transcriptomic changes were observed at 6 weeks, and only in the obese subjects: 1724 genes were significantly upregulated and 186 genes were downregulated in the vitamin D group compared with placebo. Further analyses showed several enriched gene categories connected to mitochondrial function and metabolism, and the most significantly enriched pathway was related to oxidative phosphorylation (adjusted P value 3.08 x 10(-14)). Taken together, our data suggest an effect of vitamin D supplementation on mitochondrial function in obese subjects. Conclusions: Vitamin D supplementation affects gene expression in obese, but not in normal-weight subjects. The altered genes are enriched in pathways related to mitochondrial function. The present study increases the understanding of the effects of vitamin D at the transcriptome level.
  • Mattila, Tiina; Vasankari, Tuula; Rissanen, Harri; Knekt, Paul; Sares-Jäske, Laura; Jääskeläinen, Tuija; Heliövaara, Markku (2019)
    Background and objective: Chronic obstructive pulmonary disease and low vitamin D status predict mortality, but their combined effect on mortality remains inconclusive. We aimed to investigate a joint effect of airway obstruction and vitamin D status on mortality in a nationally representative cohort. Methods: We analysed data of 6676 Finnish adults participating between 1978 and 1980 in a national health examination survey, undergoing spirometry and having all necessary data collected. We followed them up in national registers through record linkage until 31 December 2011. We categorised the subjects with obstruction using the lower limit of normal (LLN) and the measured serum 25-hydroxyvitamin-D (s-25(OH)D) into tertiles. Results: Both obstruction and low s-25(OH) D independently predicted mortality in a multivariate model adjusted also for age, sex, smoking, education, leisure physical activity, body mass index, asthma and serum C-reactive protein. However, a statistically significant (p = 0.007) interaction emerged: the adjusted mortality HRs (95% CI's) for s-25(OH)D in tertiles among the subjects without and with obstruction were 1.00 (lowest), 0.96 (0.87-1.05) and 0.89 (0.81-0.98); and 1.00, 0.96 (0.71-1.31) and 0.57 (0.40-0.80), respectively. Conclusions: In conclusion, obstruction and low s-25(OH)D predict mortality independently of each other. Our findings suggest that low vitamin D status might be particularly detrimental among subjects with obstruction.
  • Vimaleswaran, Karani S.; Berry, Diane J.; Lu, Chen; Tikkanen, Emmi; Pilz, Stefan; Hiraki, Linda T.; Cooper, Jason D.; Dastani, Zari; Li, Rui; Houston, Denise K.; Wood, Andrew R.; Michaelsson, Karl; Vandenput, Liesbeth; Zgaga, Lina; Yerges-Armstrong, Laura M.; McCarthy, Mark I.; Dupuis, Josee; Kaakinen, Marika; Kleber, Marcus E.; Jameson, Karen; Arden, Nigel; Raitakari, Olli; Viikari, Jorma; Lohman, Kurt K.; Ferrucci, Luigi; Melhus, Hakan; Ingelsson, Erik; Byberg, Liisa; Lind, Lars; Lorentzon, Mattias; Salomaa, Veikko; Campbell, Harry; Dunlop, Malcolm; Mitchell, Braxton D.; Herzig, Karl-Heinz; Pouta, Anneli; Hartikainen, Anna-Liisa; Streeten, Elizabeth A.; Theodoratou, Evropi; Jula, Antti; Wareham, Nicholas J.; Ohlsson, Claes; Frayling, Timothy M.; Kritchevsky, Stephen B.; Spector, Timothy D.; Richards, J. Brent; Lehtimaki, Terho; Ouwehand, Willem H.; Kraft, Peter; Genetic Invest Anthropometric Trai; Lokki, Marja-Liisa (2013)
  • Vogt, Susanne; Wahl, Simone; Kettunen, Johannes; Breitner, Susanne; Kastenmueller, Gabi; Gieger, Christian; Suhre, Karsten; Waldenberger, Melanie; Kratzsch, Juergen; Perola, Markus; Salomaa, Veikko; Blankenberg, Stefan; Zeller, Tanja; Soininen, Pasi; Kangas, Antti J.; Peters, Annette; Grallert, Harald; Ala-Korpela, Mika; Thorand, Barbara (2016)
    Background: Numerous observational studies have observed associations between vitamin D deficiency and cardiometabolic diseases, but these findings might be confounded by obesity. A characterization of the metabolic profile associated with serum 25-hydroxyvitamin D [25(OH)D] levels, in general and stratified by abdominal obesity, may help to untangle the relationship between vitamin D, obesity and cardiometabolic health. Methods: Serum metabolomics measurements were obtained from a nuclear magnetic resonance spectroscopy (NMR)- and a mass spectrometry (MS)-based platform. The discovery was conducted in 1726 participants of the population-based KORA-F4 study, in which the associations of the concentrations of 415 metabolites with 25(OH)D levels were assessed in linear models. The results were replicated in 6759 participants (NMR) and 609 (MS) participants, respectively, of the population-based FINRISK 1997 study. Results: Mean [standard deviation (SD)] 25(OH)D levels were 15.2 (7.5) ng/ml in KORA F4 and 13.8 (5.9) ng/ml in FINRISK 1997; 37 metabolites were associated with 25(OH) D in KORA F4 at P <0.05/415. Of these, 30 associations were replicated in FINRISK 1997 at P <0.05/37. Among these were constituents of (very) large very-low-density lipoprotein and small low-density lipoprotein subclasses and related measures like serum triglycerides as well as fatty acids and measures reflecting the degree of fatty acid saturation. The observed associations were independent of waist circumference and generally similar in abdominally obese and non-obese participants. Conclusions: Independently of abdominal obesity, higher 25(OH)D levels were associated with a metabolite profile characterized by lower concentrations of atherogenic lipids and a higher degree of fatty acid polyunsaturation. These results indicate that the relationship between vitamin D deficiency and cardiometabolic diseases is unlikely to merely reflect obesity-related pathomechanisms.
  • Enlund-Cerullo, Maria; Koljonen, Laura; Holmlund-Suila, Elisa; Hauta-Alus, Helena; Rosendahl, Jenni; Valkama, Saara; Helve, Otto; Hytinantti, Timo; Viljakainen, Heli; Andersson, Sture; Mäkitie, Outi; Pekkinen, Minna (2019)
    Context: Single nucleotide polymorphisms (SNPs) of the vitamin D binding protein encoding the GC (group component) gene affect 25-hydroxyvitamin D (25OHD) concentrations, but their influence on vitamin D status and response to vitamin D supplementation in infants is unknown. Objective: To study GC genotype-related differences in 25OHD concentrations and the response to supplementation during a vitamin D intervention study in infants. Design: In this randomized controlled trial, healthy term infants received vitamin D-3 (10 or 30 mu g/d) from 2 weeks to 24 months of age. GC SNPs rs2282679, rs4588, rs7041, and rs1155563 were genotyped. rs4588/7041 diplotype and haplotypes of rs2282679, rs4588, and rs7041 (Haplo(3SNP)) and of all four SNPs (Haplo(4SNP)) were determined. Main Outcome Measures: 25OHD measured in cord blood at birth and at 12 and 24 months during intervention. Results: A total of 913 infants were included. Minor allele homozygosity of all studied GC SNPs, their combined haplotypes, and rs4588/rs7041 diplotype 2/2 were associated with lower 25OHD concentrations at all time points in one or both intervention groups [analysis of covariance (ANCOVA) P <0.043], with the exception of rs7041, which did not affect 25OHD at birth. In the high-dose supplementation group receiving 30 mu g/d vitamin D-3, but not in those receiving 10 mu g/d, genotype of rs2282679, rs4588, and rs7041; diplotype; and Haplo(3SNP) significantly affected intervention response (repeated measurement ANCOVA P-interaction <0.019). Minor allele homozygotes had lower 25OHD concentrations and smaller increases in 25OHD throughout the intervention. Conclusions: In infants, vitamin D binding protein genotype affects 25OHD concentration and efficiency of high-dose vitamin D-3 supplementation.
  • Hauta-alus, Helena H.; Kajantie, Eero; Holmlund-Suila, Elisa M.; Rosendahl, Jenni; Valkama, Saara M.; Enlund-Cerullo, Maria; Helve, Otto M.; Hytinantti, Timo K.; Viljakainen, Heli; Andersson, Sture; Mäkitie, Outi (2019)
    Context: The relationship of maternal and infant 25-hydroxyvitamin D concentration [25(OH)D] with infant growth is unclear. Objective: Our objective was to explore whether 25(OH)D in pregnancy, umbilical cord blood (UCB), or in infancy was associated with infant growth. Design: This study involved 798 healthy infants and their mothers in Finland. We assessed 25(OH)D during pregnancy, from UCB at birth, and from the infant at the age of 12 months. Main Outcome Measures: Infant length, weight, length-adjusted weight, and head circumference at 6 and 12 months and midupper-arm circumference at 12 months. Results: Of the mothers and infants, 96% and 99% were vitamin D sufficient [25(OH)D >= 50 nmol/L], respectively. Mothers with pregnancy 25(OH)D >125 nmol/L had the shortest, lightest (in weight), and thinnest (in length-adjusted weight) infants at 6 months (P for all <0.05). For each 10 nmol/L higher UCB 25(OH)D, the infants were 0.03 SD score (SDS) shorter at 6 months (95% CI -0.05 to -0.01), adjusted for birth size, infant 25(OH)D, and parental height. Higher UCB 25(OH)D associated with smaller head circumference at 6 and 12 months (P for all 125 nmol/L had the thinnest infants at 12 months (P = 0.021). For each 10 nmol/L higher infant 25(OH)D, the infants were 0.03 SDS lighter (-0.05 to -0.01) and 0.03 SDS thinner (-0.05 to 0.00) at 12 months. Conclusions: Our results suggest that high pregnancy, cord blood, and infant vitamin D concentration may have disadvantageous effects on infant growth.
  • Saarnio, Elisa; Pekkinen, Minna; Itkonen, Suvi T.; Kemi, Virpi; Karp, Heini; Ivaska, Kaisa K.; Risteli, Juha; Koivula, Marja-Kaisa; Kärkkäinen, Merja; Mäkitie, Outi; Sievänen, Harri; Lamberg-Allardt, Christel (2018)
    Background Studies have shown altered vitamin D metabolism in obesity. We assessed differences between obese and normal-weight subjects in total, free, and bioavailable 25-hydroxyvitamin D (25(OH) D, 25(OH) D-Free, and 25(OH) D-Bio, respectively), vitamin D binding protein (DBP), parathyroid hormone (PTH) and bone traits. Methods 595 37-47-year-old healthy Finnish men and women stratified by BMI were examined in this cross-sectional study. Background characteristic and intakes of vitamin D and calcium were collected. The concentrations of 25(OH) D, PTH, DBP, albumin and bone turnover markers were determined from blood. 25(OH) D-Free and 25(OH) D-Bio were calculated. pQCT was performed at radius and tibia. Results Mean +/- SE (ANCOVA) 25(OH) D-Free (10.8 +/- 0.6 vs 12.9 +/- 0.4 nmol/L; P = 0.008) and 25(OH) DBio (4.1 +/- 0.3 vs 5.1 +/- 0.1 nmol/L; P = 0.003) were lower in obese than in normal-weight women. In men, 25(OH) D (48.0 +/- 2.4 vs 56.4 +/- 2.0 nmol/L, P = 0.003), 25(OH) D-Free (10.3 +/- 0.7 vs 12.5 +/- 0.6 pmol/L; P = 0.044) and 25(OH) D-Bio (4.2 +/- 0.3 vs 5.1 +/- 0.2 nmol/L; P = 0.032) were lower in obese. Similarly in all subjects, 25(OH) D, 25(OH) D-Free and 25(OH) D-Bio were lower in obese (P Conclusions The associations between BMI and 25(OH) D, 25(OH) D-Free, and 25(OH) D-Bio, DBP, and PTH suggest that obese subjects may differ from normal-weight subjects in vitamin D metabolism. BMI associated positively with trabecular bone traits and CSI in our study, and slightly negatively with cortical bone traits. Surprisingly, there was a negative association of free and bioavailable 25(OH) D and some of the bone traits in obese women.
  • Hauta-alus, Helena H.; Viljakainen, Heli T.; Holmlund-Suila, Elisa M.; Enlund-Cerullo, Maria; Rosendahl, Jenni; Valkama, Saara M.; Helve, Otto M.; Hytinantti, Timo K.; Mäkitie, Outi M.; Andersson, Sture (2017)
    Background: Maternal vitamin D status has been associated with both gestational diabetes mellitus (GDM) and fetal growth restriction, however, the evidence is inconsistent. In Finland, maternal vitamin D status has improved considerably due to national health policies. Our objective was to compare maternal 25-hydroxy vitamin D concentrations [25(OH)D] between mothers with and without GDM, and to investigate if an association existed between maternal vitamin D concentration and infant birth size. Methods: This cross-sectional study included 723 mother-child pairs. Mothers were of Caucasian origin, and infants were born at term with normal birth weight. GDM diagnosis and birth size were obtained from medical records. Maternal 25(OH)D was determined on average at 11 weeks of gestation in pregnancy and in umbilical cord blood (UCB) at birth. Results: GDM was observed in 81 of the 723 women (11%). Of the study population, 97% were vitamin D sufficient [25(OH)D >= 50 nmol/L]. There was no difference in pregnancy 25(OH)D concentration between GDM and non-GDM mothers (82 vs 82 nmol/L, P = 0.99). Regression analysis confirmed no association between oral glucose tolerance test results and maternal 25(OH)D (P > 0.53). Regarding the birth size, mothers with optimal pregnancy 25(OH)D (>= 80 nmol/L) had heavier newborns than those with suboptimal pregnancy 25(OH)D (P = 0.010). However, mothers with optimal UCB 25(OH) D had newborns with smaller head circumference than those with suboptimal 25(OH)D (P = 0.003), which was further confirmed as a linear association (P = 0.024). Conclusions: Maternal vitamin D concentration was similar in mothers with and without GDM in a mostly vitamin D sufficient population. Associations between maternal vitamin D status and birth size were inconsistent. A sufficient maternal vitamin D status, specified as 25(OH)D above 50 nmol/L, may be a threshold above which the physiological requirements of pregnancy are achieved.
  • Ala-Houhala, Meri J.; Karppinen, Toni; Vahavihu, Katja; Kautiainen, Hannu; Dombrowski, Yvonne; Snellman, Erna; Schauber, Juergen; Reunala, Timo (2014)
  • TEDDY STUDY GRP; Norris, Jill M.; Lee, Hye-Seung; Frederiksen, Brittni; Erlund, Iris; Toppari, Jorma; Sundvall, Jouko; Virtanen, Suvi M.; Knip, Mikael (2018)
    We examined the association between plasma 25-hydroxyvitamin D [25(OH)D] concentration and islet autoimmunity (IA) and whether vitamin D gene polymorphisms modify the effect of 25(OH)D on IA risk. We followed 8,676 children at increased genetic risk of type 1 diabetes at six sites in the U.S. and Europe. We defined IA as positivity for at least one autoantibody (GADA, IAA, or IA-2A) on two or more visits. We conducted a risk set sampled nested case-control study of 376 IA case subjects and up to 3 control subjects per case subject. 25(OH)D concentration was measured on all samples prior to, and including, the first IA positive visit. Nine polymorphisms in VDR, CYP24A, CYP27B1, GC, and RXRA were analyzed as effect modifiers of 25(OH)D. Adjusting for HLA-DR-DQ and ancestry, higher childhood 25(OH)D was associated with lower IA risk (odds ratio = 0.93 for a 5 nmol/L difference; 95% CI 0.89, 0.97). Moreover, this association was modified by VDR rs7975232 (interaction P = 0.0072), where increased childhood 25(OH)D was associated with a decreasing IA risk based upon number of minor alleles: 0 (1.00; 0.93, 1.07), 1 (0.92; 0.89, 0.96), and 2 (0.86; 0.80, 0.92). Vitamin D and VDR may have a combined role in IA development in children at increased genetic risk for type 1 diabetes.
  • Itkonen, Suvi T.; Pajula, Elina T.; Dowling, Kirsten G.; Hull, George L. J.; Cashman, Kevin D.; Lamberg-Allardt, Christel J. E. (2018)
    Ultraviolet-irradiated yeast (Saccharomyces cerevisiae) can be used to biofortify bakery products with vitamin D, but in bread, it was not effective in increasing serum 25-hydroxyvitamin D [25(OH)D] in humans, possibly because of the low digestibility of the yeast matrix. We investigated the effects of vitamin D-2-rich intact yeast cells and their separated fraction, yeast cell walls, which we hypothesized to provide vitamin D-2 in a more bioavailable form, on serum 25(OH)D and its metabolites in growing female Sprague-Dawley rats (n = 54) compared to vitamin D-2 and D-3 supplements (8 treatment groups: 300 or 600 IU vitamin D/d, and a control group, 8-week intervention). The D-3 supplement groups had the highest 25(OH)D concentrations, and the vitamin D-2 supplement at the 600-IU dose increased 25(OH)D better than any yeast form (P <.001 for all, analysis of covariance, adjusted for body weight). There were no significant differences between the yeast forms at the same dose (P > .05). Serum 24,25-dihydroxyvitamin D (a vitamin D catabolite) concentrations and the trend in the differences between the groups were in line with 25 (OH)D (P <.001 for all). The 24,25-dihydroxyvitamin D to 25(OH)D ratio between the D-2 supplement and the yeast groups did not differ (P > .05). These findings do not support the hypothesis: the ability of the different ultraviolet-treated vitamin D-2-containing yeast forms to increase 25(OH)D did not differ, and the poor bioavailability of vitamin D-2 in the yeasts compared D-3 or D-2 supplements could not be explained by the increased vitamin D catabolism in the yeast-treated groups. (C) 2018 Elsevier Inc. All rights reserved.
  • Gao, Jing; Törölä, Tanja; Li, Chuan-Xing; Ohlmeier, Steffen; Toljamo, Tuula; Nieminen, Pentti; Hattori, Noboru; Pulkkinen, Ville; Iwamoto, Hiroshi; Mazur, Witold (2020)
    Introduction: The vitamin D binding protein (VDBP, also known as GC-globulin) and vitamin D deficiency have been associated with chronic obstructive pulmonary disease (COPD). rs7041 and rs4588 are two single nucleotide polymorphisms of the VDBP gene, including three common allelic variants (GC1S, GC1F and GC2). Previous studies primarily assessed the serum levels of vitamin D and VDBP in COPD. However, less is known regarding the impact of the local release of VDBP on COPD lung function. Thus, we examined the association of sputum and plasma VDBP with lung function at baseline and at four years, and examined potential genetic polymorphism interactions. Methods: The baseline levels of sputum VDBP, plasma VDBP and plasma 25-OH vitamin D, as well as the GC rs4588 and rs7041 genotypes, were assessed in a 4-year Finnish follow-up cohort (n = 233) of non-smokers, and smokers with and without COPD. The associations between the VDBP levels and the longitudinal decline of lung function were further analysed. Results: High frequencies of the haplotypes in rs7041/rs4588 were homozygous GC1S/1S (42.5%). Higher sputum VDBP levels in stage I and stage II COPD were observed only in carriers with GC1S/1S genotype when compared with non-smokers (p = 0.034 and p = 0.002, respectively). Genotype multivariate regression analysis indicated that the baseline sputum VDBP and FEV1/FVC ratio at baseline independently predicted FEV1% at follow-up. Discussion and Conclusion: The baseline sputum VDBP expression was elevated in smokers with COPD among individuals with the GC1S/1S genotype, and predicted follow-up airway obstruction. Our results suggest that the GC polymorphism should be considered when exploring the potential of VDBP as a biomarker for COPD.
  • Helve, Otto; Viljakainen, Heli; Holmlund-Suila, Elisa; Rosendahl, Jenni; Hauta-alus, Helena; Enlund-Cerullo, Maria; Valkama, Saara; Heinonen, Kati; Räikkönen, Katri; Hytinantti, Timo; Mäkitie, Outi; Andersson, Sture (2017)
    Background: Vitamin D is important for bone mass accrual during growth. Additionally, it is considered a requirement for a multitude of processes associated with, for example, the development of immunity. Many countries apply vitamin D supplementation strategies in infants, but the guidelines are not based on scientific evidence and aim at prevention of rickets. It remains unclear whether the recommended doses are sufficient for the wide array of other effects of vitamin D. The VIDI trial performed in Finland is the first large randomised controlled study for evaluation of the effects of different vitamin D supplemental doses in infancy on: 1. bone strength 2. infections and immunity 3. allergy, atopy and asthma 4. cognitive development 5. genetic regulation of mineral homeostasis Methods/Design: VIDI, a randomised controlled double-blinded single-centre intervention study is conducted in infants from the age of 2 weeks to 24 months. Participants, recruited at Helsinki Maternity Hospital, are randomised to receive daily either 10 mu g (400 IU) or 30 mu g (1 200 IU) of vitamin D3 supplementation. Both groups are assessed at 6 months of age for calcium homeostasis, and at 12 and 24 months of age for parameters associated with bone strength, growth, developmental milestones, infections, immunity, atopy-related diseases, and genetic factors involved in these functions. Discussion: The study enables evaluation of short and long term effects of supplemental vitamin D on growth, immune functions and skeletal and developmental parameters in infants, and the effects of genetic factors therein. The results enable institution of evidence-based guidelines for vitamin D supplementation in infancy.
  • Peterlik, Meinrad; Boonen, Steven; Cross, Heide S.; Lamberg-Allardt, Christel Johanna Emilia (2009)
  • Maddock, Jane; Zhou, Ang; Cavadino, Alana; Kuzma, Elzbieta; Bao, Yanchun; Smart, Melissa C.; Saum, Kai-Uwe; Schoettker, Ben; Engmann, Jorgen; Kjaergaard, Marie; Karhunen, Ville; Zhan, Yiqiang; Lehtimaki, Terho; Rovio, Suvi P.; Byberg, Liisa; Lahti, Jari; Marques-Vidal, Pedro; Sen, Abhijit; Perna, Laura; Schirmer, Henrik; Singh-Manoux, Archana; Auvinen, Juha; Hutri-Kahonen, Nina; Kahonen, Mika; Kilander, Lena; Raikkonen, Katri; Melhus, Hakan; Ingelsson, Erik; Guessous, Idris; Petrovic, Katja E.; Schmidt, Helena; Schmidt, Reinhold; Vollenweider, Peter; Lind, Lars; Eriksson, Johan G.; Michaelsson, Karl; Raitakari, Olli T.; Hagg, Sara; Pedersen, Nancy L.; Herzig, Karl-Heinz; Jarvelin, Marjo-Riitta; Veijola, Juha; Kivimaki, Mika; Jorde, Rolf; Brenner, Hermann; Kumari, Meena; Power, Chris; Llewellyn, David J.; Hypponen, Elina (2017)
    The causal nature of the association between hypovitaminosis D and poor cognitive function in mid-to later-life is uncertain. Using a Mendelian randomisation(MR) approach, we examined the causal relationship between 25(OH)D and cognitive function. Data came from 172,349 participants from 17 cohorts. DHCR7(rs12785878), CYP2R1 rs12794714) and their combined synthesis score were chosen to proxy 25(OH)D. Cognitive tests were standardised into global and memory scores. Analyses were stratified by 25(OH)D tertiles, sex and age. Random effects meta-analyses assessed associations between 25(OH)D and cognitive function. Associations of serum 25(OH)D with global and memoryrelated cognitive function were non-linear (lower cognitive scores for both low and high 25(OH)D, p(curvature)
  • Itkonen, Suvi T.; Erkkola, Maijaliisa; Lamberg-Allardt, Christel J. E. (2018)
    Fluid milk products are systematically, either mandatorily or voluntarily, fortified with vitamin D in some countries but their overall contribution to vitamin D intake and status worldwide is not fully understood. We searched the PubMed database to evaluate the contribution of vitamin D-fortified fluid milk products (regular milk and fermented products) to vitamin D intake and serum or plasma 25-hydroxyvitamin D (25(OH)D) status in observational studies during 1993-2017. Twenty studies provided data on 25(OH)D status (n = 19,744), and 22 provided data on vitamin D intake (n = 99,023). Studies showed positive associations between the consumption of vitamin D-fortified milk and 25(OH)D status in different population groups. In countries with a national vitamin D fortification policy covering various fluid milk products (Finland, Canada, United States), milk products contributed 28-63% to vitamin D intake, while in countries without a fortification policy, or when the fortification covered only some dairy products (Sweden, Norway), the contribution was much lower or negligible. To conclude, based on the reviewed observational studies, vitamin D-fortified fluid milk products contribute to vitamin D intake and 25(OH)D status. However, their impact on vitamin D intake at the population level depends on whether vitamin D fortification is systematic and policy-based.
  • Adebayo, Folasade Abiola; Itkonen, Suvi Tuulikki; Öhman, Taina; Skaffari, Essi; Saarnio, Elisa Maria; Erkkola, Maijaliisa; Cashman, Kevin; Lamberg-Allardt, Christel Johanna Emilia (2018)
    Insufficient vitamin D status (serum 25-hydroxyvitamin D (S-25(OH)D)<50 nmol/l) is common among immigrants living at the northern latitudes. We investigated ethnic differences in response of S-25(OH)D to vitamin D3 supplementation, through a 5-month randomised controlled trial, in East African and Finnish women in Southern Finland (60°N) from December 2014 to May 2015. Vitamin D intakes (dietary and supplemental) were also examined. Altogether, 191 subjects were screened and 147 women (East Africans n 72, Finns n 75) aged 21–64 years were randomised to receive placebo or 10 or 20 µg of vitamin D3/d. S-25(OH)D concentrations were assessed by liquid chromatography–tandem MS. At screening, 56 % of East Africans and 9 % of Finns had S-25(OH)D<50 nmol/l. Total vitamin D intake was higher in East Africans than in Finns (24·2 (sd 14·3) v. 15·2 (sd 13·4) µg/d, P<0·001). Baseline mean S-25(OH)D concentrations were higher in Finns (60·5 (sd=16·3) nmol/l) than in East Africans (51·5 (sd 15·4) nmol/l) (P=0·001). In repeated-measures ANCOVA (adjusted for baseline S-25(OH)D), mean S-25(OH)D increased by 8·5 and 10·0 nmol/l with a 10-µg dose and by 10·7 and 17·1 nmol/l with a 20-µg dose for Finns and East Africans, respectively (P>0·05 for differences between ethnic groups). In conclusion, high prevalence of vitamin D insufficiency existed among East African women living in Finland, despite higher vitamin D intake than their Finnish peers. Moderate vitamin D3 supplementation was effective in increasing S-25(OH)D in both groups of women, and no ethnic differences existed in the response to supplementation.
  • Pekkinen, Minna; Viljakainen, Heli; Saarnio, Elisa; Lamberg-Allardt, Christel; Mäkitie, Outi (2012)
  • Lumme, Johanna; Mottonen, Merja; Pokka, Tytti; Makitie, Outi; Harila-Saari, Arja; Niinimaki, Riitta (2019)