Browsing by Subject "vitamin D"

Sort by: Order: Results:

Now showing items 1-19 of 19
  • 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.
  • 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.
  • Österlund, Michaela (Helsingfors universitet, 2017)
    Detta arbete är en litteraturstudie vars syfte är att undersöka vetenskapliga artiklar för att ta reda på hur D-vitamin påverkar parodontala vävnaden och om det finns belägg för att D-vitamin har en positiv effekt på parodontala hälsan. D-vitamin är ett prohormon som reglerar immunförsvaret och kroppens absorption av kalcium och fosfor. Parodontit är en kronisk inflammatorisk sjukdom som bryter ner tänders stödjevävnad samt käkarnas alveolarben och ger upphov till tandlossning. Denna studie letar i den vetenskapliga litteraturen om det finns kausalitets samband mellan D-vitaminbrist och parodontit eftersom båda tillstånden är skelettala och inflammatoriska sjukdomar. Både parodontit och D-vitaminbrist är vanligt förekommande i den finska befolkningen. Detta arbete är baserat på litteratursökning i PubMed, Melinda, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews och internet hemsidan Litteraturgranskningens resultat är att sambandet mellan D-vitamin halten i serum och parodontal infektion är svag. Populations studier visar att D-vitamin brist har försumbar gynnsam effekt på parodontal infektion. Däremot har D-vitamin i teorin positiv effekt på alveolarbenets mineraldensitet och immunförsvar. Denna studie visar att D-vitaminbrist kan vara orsaken till ett svagt parodontologiskt behandlingssvar om andra starkare parodontologiska riskfaktorer är uteslutna.
  • Äikäs, Lauri (Helsingin yliopisto, 2021)
    Abstract Introduction: Atherosclerotic cardiovascular diseases (ASCVD) cause the biggest burden on our healthcare system and cause most premature deaths. Risk for ASCVD can be lowered by lifestyle choices and medication, as well as several therapeutics such as ethyl eicosapentaenoic acid (E-EPA) supplementation. Here we aimed to investigate the effect of EEPA intervention on known ASCVD risk factors including circulating lipoprotein levels as well as low-density lipoprotein (LDL) aggregation susceptibility, a new independent risk factor for ASCVD. Study design: A study group of 39 healthy men and women participated in a 4-week long dietary supplement trial with 3.9 g/day of E-EPA. A dose of 75 µg/day of vitamin D was included in the E-EPA capsules. Blood samples were drawn before the trial, at weeks 1 and 4 of the intervention and 1 week after the intervention. The study was an open design where participants’ own baseline measurements were used to measure changes. Outcomes: The mean plasma cholesterol concentration was reduced from 3.8 mmol/l to 3.6 mmol/l (p=0.0038 one-way ANOVA) after one week of E-EPA supplementation and remained the same until the end of study period. This change was followed by a change in plasma LDL (p=0.0028 one-way ANOVA) and triglyceride (p=0.0004 one-way ANOVA) concentrations after four week and one week of E-EPA supplementation, respectively. Vitamin D levels increased on average by 18%, showcasing a lower relative response than seen in other vitamin D trials, which can be attributed to high effective baseline concentrations of vitamin D in our study group and the related negative feedback system. LDL aggregation susceptibility did not significantly change in the entire group. However, we discovered that the change in LDL aggregation susceptibility correlated negatively ( = -0.451, p = 0.0039) with the baseline LDL aggregation susceptibility. Thus, LDL aggregation decreased in participants having aggregation-prone LDL at baseline. This finding highlights a possibility that participants with higher LDL aggregation susceptibility may benefit from addition of E-EPA to their diet.
  • Karppinen, Toni; Ylianttila, Lasse; Kautiainen, Hannu; Reunala, Timo; Snellman, Erna (2015)
    Empowering heliotherapy aims at clinical healing and improved coping with psoriasis and atopic dermatitis, but evidence of long-term effects is scarce. We studied the effect of 2-week empowering heliotherapy in the Canary Islands on clinical outcome and quality of life in 22 psoriasis and 13 atopic dermatitis patients. Empowerment consisted of meeting peers, sharing experiences and performing physical and mental practices. Using the self-administered PASI (SAPASI) psoriasis was alleviated statistically significantly during heliotherapy (p <0.001), and the treatment effect was still detectable 3 months later (p <0.001). Atopic dermatitis was improved (p <0.001) when assessed with the patient-oriented SCORAD (PO-SCORAD), and the effect was still obvious 3 months later (p = 0.002). During heliotherapy the dermatology life quality index (DLQI) improved in both groups (p <0.001), persisting in atopic patients for up to 3 months (p = 0.002), but not in psoriasis patients. In conclusion, a 2-week empowered heliotherapy showed a long-lasting improvement in psoriasis and atopic dermatitis disease activity, and also in the quality of life of atopic patients.
  • Sallinen, Riitta J.; Dethelsen, Olga; Ruotsalainen, Sanni; Mills, Robert D.; Miettinen, Timo; Jääskeläinen, Tuija E.; Lundqvist, Annamari; Kyllönen, Eero; Kröger, Heikki; Karppinen, Jaro; Lamberg-Allardt, Christel; Viljakainen, Heli; Kaunisto, Mari A.; Kallioniemi, Olli (2021)
    Background Genetic factors modify serum 25-hydroxyvitamin D [25(OH)D] concentration and can affect the optimal intake of vitamin D. Objectives We aimed to personalize vitamin D supplementation by applying knowledge of genetic factors affecting serum 25(OH)D concentration. Methods We performed a genome-wide association study of serum 25(OH)D concentration in the Finnish Health 2011 cohort (n = 3339) using linear regression and applied the results to develop a population-matched genetic risk score (GRS) for serum 25(OH)D. This GRS was used to tailor vitamin D supplementation for 96 participants of a longitudinal Digital Health Revolution (DHR) Study. The GRS, serum 25(OH)D concentrations, and personalized supplementation and dietary advice were electronically returned to participants. Serum 25(OH)D concentrations were assessed using immunoassays and vitamin D intake using FFQs. In data analyses, cross-sectional and repeated-measures statistical tests and models were applied as described in detail elsewhere. Results GC vitamin D-binding protein and cytochrome P450 family 2 subfamily R polypeptide 1 genes showed genome-wide significant associations with serum 25(OH)D concentration. One single nucleotide polymorphism from each locus (rs4588 and rs10741657) was used to develop the GRS. After returning data to the DHR Study participants, daily vitamin D supplement users increased from 32.6% to 60.2% (P = 6.5 x 10(-6)) and serum 25(OH)D concentration from 64.4 +/- 20.9 nmol/L to 68.5 +/- 19.2 nmol/L (P = 0.006) between August and November. Notably, the difference in serum 25(OH)D concentrations between participants with no risk alleles and those with 3 or 4 risk alleles decreased from 20.7 nmol/L to 8.0 nmol/L (P = 0.0063). Conclusions We developed and applied a population-matched GRS to identify individuals genetically predisposed to low serum 25(OH)D concentration. We show how the electronic return of individual genetic risk, serum 25(OH)D concentrations, and factors affecting vitamin D status can be used to tailor vitamin D supplementation. This model could be applied to other populations and countries.
  • Sucksdorff, Minna; Brown, Alan S.; Chudal, Roshan; Surcel, Helja-Marja; Hinkka-Yli-Salomaki, Susanna; Cheslack-Postava, Keely; Gyllenberg, David; Sourander, Andre (2021)
    Objective: Recent evidence has highlighted the importance of vitamin D in the development of the central nervous system. Some studies have shown an association between maternal vitamin D deficiency during pregnancy and offspring attention-deficit/hyperactivity disorder (ADHD) symptoms based on parent or teacher ratings. There are no previous studies on early pregnancy 25-hydroxyvitamin D [25(OH)D] levels and the risk of diagnosed offspring ADHD. Our aim was to examine maternal 25(OH)D levels in early pregnancy and offspring ADHD. Method: In this nationwide population-based case-control study, 1,067 ADHD cases (born between 1998 and 1999 and diagnosed according to the International Classification of Diseases) and 1,067 matched controls were identified from Finnish registers. Maternal 25(OH)D levels were measured using quantitative immunoassay from maternal sera, collected during the first trimester and archived in the national biobank. Conditional logistic regression was used to examine the association between maternal 25(OH)D and offspring ADHD. Results: There was a significant association between decreasing log-transformed maternal 25(OH)D levels and offspring ADHD both in the unadjusted analyses (odds ratio 1.65; 95% CI 1.33-2.05; p <.001) and in the analyses adjusting for maternal socioeconomic status and age (odds ratio 1.45; 95% CI 1.15-1.81; p = .002). Analyses by quintiles of maternal 25(OH)D levels in the lowest versus highest quintile revealed an adjusted odds ratio for offspring ADHD of 1.53 (95% CI 1.11-2.12; p = .010). Conclusion: This study demonstrated an association between low maternal 25(OH)D during pregnancy and an elevated risk for offspring ADHD. If replicated in independent samples, this finding may have significant public health implications.
  • Ala-Houhala, Meri J.; Karppinen, Toni; Vahavihu, Katja; Kautiainen, Hannu; Dombrowski, Yvonne; Snellman, Erna; Schauber, Juergen; Reunala, Timo (2014)
  • Koljonen, Laura; Enlund-Cerullo, Maria; Hauta-Alus, Helena; Holmlund-Suila, Elisa; Valkama, Saara; Rosendahl, Jenni; Andersson, Sture; Pekkinen, Minna; Mäkitie, Outi (2021)
    Context: Phosphate homeostasis and its modifiers in early childhood are inadequately characterized. Objective: To determine physiological plasma phosphate concentration and modifying factors in healthy infants at 12 to 24 months of age. Design: This study included 525 healthy infants (53% girls), who participated in a randomized vitamin D intervention trial and received daily vitamin D3 supplementation of either 10 or 30 μg from age 2 weeks to 24 months. Biochemical parameters were measured at 12 and 24 months. Dietary phosphate intake was determined at 12 months. Main Outcome Measures: Plasma phosphate concentrations at 12 and 24 months of age. Results: Mean (SD) phosphate concentration decreased from 12 months (1.9±0.15 mmol/L) to 24 months (1.6±0.17 mmol/L) of age (P<0.001 for repeated measurements). When adjusted by covariates, such as body size, creatinine, serum 25-hydroxyvitamin D, intact and C-terminal fibroblast growth factor 23, mean plasma phosphate was higher in boys than girls during follow-up (P=0.019). Phosphate concentrations were similar in the vitamin D intervention groups (P>0.472 for all). Plasma iron was associated positively with plasma phosphate at both time points (B, 0.006 and 0.005; 95% CI, 0.004-0.009 and 0.002-0.008; P<0.001 at both time points, respectively). At 24 months of age, the main modifier of phosphate concentration was plasma creatinine (B, 0.007; 95% CI 0.003-0.011, P<0.001). Conclusion: Plasma phosphate concentration decreased from age 12 to 24 months. In infants and toddlers, the strongest plasma phosphate modifiers were sex, iron, and creatinine, whereas vitamin D supplementation did not modify phosphate concentrations.
  • Pilz, Stefan; Maerz, Winfried; Cashman, Kevin D.; Kiely, Mairead E.; Whiting, Susan J.; Holick, Michael F.; Grant, William B.; Pludowski, Pawel; Hiligsmann, Mickael; Trummer, Christian; Schwetz, Verena; Lerchbaum, Elisabeth; Pandis, Marlene; Tomaschitz, Andreas; Gruebler, Martin R.; Gaksch, Martin; Verheyen, Nicolas; Hollis, Bruce W.; Rejnmark, Lars; Karras, Spyridon N.; Hahn, Andreas; Bischoff-Ferrari, Heike A.; Reichrath, Jörg; Jorde, Rolf; Elmadfa, Ibrahim; Vieth, Reinhold; Scragg, Robert; Calvo, Mona S.; van Schoor, Natasja M.; Bouillon, Roger; Lips, Paul; Itkonen, Suvi T.; Martineau, Adrian R.; Lamberg-Allardt, Christel; Zittermann, Armin (2018)
    Vitamin D deficiency can lead to musculoskeletal diseases such as rickets and osteomalacia, but vitamin D supplementation may also prevent extraskeletal diseases such as respiratory tract infections, asthma exacerbations, pregnancy complications and premature deaths. Vitamin D has a unique metabolism as it is mainly obtained through synthesis in the skin under the influence of sunlight (i.e., ultraviolet-B radiation) whereas intake by nutrition traditionally plays a relatively minor role. Dietary guidelines for vitamin D are based on a consensus that serum 25-hydroxyvitamin D (25[OH]D) concentrations are used to assess vitamin D status, with the recommended target concentrations ranging from >= 25 to >= 50 nmol/L (>= 10->= 20 ng/mL), corresponding to a daily vitamin D intake of 10 to 20 mu g (400-800 international units). Most populations fail to meet these recommended dietary vitamin D requirements. In Europe, 25(OH)D concentrations <30 nmol/L (12 ng/mL) and <50 nmol/L (20 ng/mL) are present in 13.0 and 40.4% of the general population, respectively. This substantial gap between officially recommended dietary reference intakes for vitamin D and the high prevalence of vitamin D deficiency in the general population requires action from health authorities. Promotion of a healthier lifestyle with more outdoor activities and optimal nutrition are definitely warranted but will not erase vitamin D deficiency and must, in the case of sunlight exposure, be well balanced with regard to potential adverse effects such as skin cancer. Intake of vitamin D supplements is limited by relatively poor adherence (in particular in individuals with low-socioeconomic status) and potential for overdosing. Systematic vitamin D food fortification is, however, an effective approach to improve vitamin D status in the general population, and this has already been introduced by countries such as the US, Canada, India, and Finland. Recent advances in our knowledge on the safety of vitamin D treatment, the dose-response relationship of vitamin D intake and 25(OH)D levels, as well as data on the effectiveness of vitamin D fortification in countries such as Finland provide a solid basis to introduce and modify vitamin D food fortification in order to improve public health with this likewise cost-effective approach.
  • EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA); Turck, Dominique; Heinonen, Marina (2021)
    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of calcidiol monohydrate as a novel food (NF) pursuant to Regulation (EU) 2015/2283, including its bioavailability as a metabolite of vitamin D3 when added for nutritional purposes to food supplements. The NF is produced chemically. It is proposed in food supplements up to 10 lg/day for individuals > 11 years of age, including pregnant and lactating women and up to 5 lg/day in 3- to 10-year-old children. The production process, composition, specifications and stability of the NF do not raise safety concerns. Animal and human data indicate efficient absorption. The NF contains a fraction of nanoparticles, which are fat soluble and unlikely to reach systemic distribution. There are no concerns regarding genotoxicity. Human adult studies do not raise safety concerns. Combined intake estimates of calcidiol from the NF and calcidiol and vitamin D from the diet were below the tolerable upper intake level (UL) for vitamin D for subjects above 11 years of age. The achieved mean serum 25(OH)D concentration in adults supplemented with 10 lg NF per day remained below 200 nmol/L. The Panel concludes that the NF is safe under the proposed conditions of use and use levels for individuals > 11 years old, including pregnant and lactating women. The applicant did not provide data on the bioavailability and safety of the NF in children. The combined intake estimation in children (3-10 years) is close to the UL for vitamin D. Therefore, the Panel could not conclude on the safety of consumption of the NF in children (3-10 years) at the proposed daily intake. The NF is a bioavailable source of the biologically active metabolite of vitamin D, i.e. 1,25-dihydroxyvitamin D. (C) 2021 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.
  • EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA); Turck, Dominique; Heinonen, Marina (2021)
    In 2014, the EFSA NDA Panel concluded that UV-treated baker's yeast containing up to 3.5 Mio IU of vitamin D/100 g, is safe under the proposed conditions of use for yeast-leavened breads, rolls and fine bakery wares, and food supplements. Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on an application for an extension of the use of UV-treated baker's yeast as a novel food (NF) pursuant to Regulation (EU) 2015/2283. In this extension of use, the applicant proposed a broad range of food categories to which the NF can be added. On the basis of the proposed uses and maximum use levels, the Panel estimated the potential exposure to vitamin D from the NF and the potential combined exposure to vitamin D including also exposure from the background diet and food supplements. The Panel notes that the upper level (UL) for one age group, i.e. children aged 4-10 years, is exceeded by 4%, when summing up the highest P95 estimate for the background diet (including food supplements) and the highest P95 estimate for vitamin D from the NF under the proposed uses and maximum use levels. The Panel notes, however, the highly conservative approach for estimating the potential intake of vitamin D from the NF, given that the applicant has proposed 34 FoodEx2 level 2 food categories. Thus, the Panel considers that the UL for children aged between 4 and 10 years is highly unlikely to be exceeded. The Panel concludes that the NF is safe under the proposed conditions of use. (C) 2021 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.
  • Adebayo, Folasade; Itkonen, Suvi; Öhman, Taina; Kiely, Mairead E; Cashman, Kevin; Lamberg-Allardt, Christel (2021)
    The safety considerations of food-based solutions for vitamin D deficiency prevention, such as fortification and supplementation, are critical. On the basis of collective data from 20 randomized controlled trials (RCTs) and 20 national healthy surveys, as well as prospective cohort studies (PCSs) across the ODIN project (“Food-based solutions for optimal vitamin D nutrition and health through the life cycle”, FP7-613977), we analyzed the potential safety issues arising from vitamin D intakes and/or supplementation. These adverse consequences included high serum 25-hydroxyvitamin D (S-25(OH)D) concentrations (>125 nmol/L), high serum calcium concentrations, and vitamin D intakes in excess of the tolerable upper intake levels (ULs). In the RCTs (n = 3353, with vitamin D doses from 5–175 µg/day), there were no reported adverse effects. The prevalence of high S-25(OH)D was <10% when vitamin D supplements were administered, and <0.1% for fortified foods. Elevated serum calcium was observed among <0.5% in both administration types. No ODIN RCT participants exceeded the age-specific ULs. In observational studies (n = 61,082), the prevalence of high 25(OH)D among children/adolescents, adults, and older adults was <0.3%, with no evidence of adverse effects. In conclusion, high S-25(OH)D concentrations >125 nmol/L were rare in the RCTs and PCSs, and no associated adverse effects were observed.
  • EFSA Panel Nutr Novel Foods Food A; Turck, Dominique; Heinonen, Marina (2020)
    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on vitamin D-2 mushroom powder as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is an ingredient produced from Agaricus bisporus mushrooms that have been exposed to ultraviolet (UV) light to induce the conversion of provitamin D-2 (ergosterol) to vitamin D-2 (ergocalciferol). The NF contains concentrations of vitamin D provided by vitamin D-2 in the ranges of 1,000-1,300 mu g/g. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods and beverages, including food for special medical purposes and food supplements. The target population is the general population except for food supplements, for which the target population is individuals above seven months of age. The Panel concludes that the NF, used as an ingredient, is safe for the general population at the proposed condition of use in foods and beverages and that the NF used as a food supplement, is safe for individuals above 1 year. The Panel, however, notes that the UL for infants aged 0-6 months may be exceeded in high consumers of infant formula (IF) and/or follow-on formula (FoF) that may also be high consumers of foods fortified with the NF and for infants aged 7-12 months consuming a daily vitamin D oral supplementation of 10 mu g. However, the Panel considers this scenario unlikely as complementary feeding in high consumers of IF and/or FoF may be limited. Furthermore, the combined consumption of vitamin D via fortified foods and supplements does not specifically concern this NF application. The Panel concludes that the NF is safe under the proposed conditions of use for the proposed target populations. (C) 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.
  • Karppinen, Toni; Ala-Houhala, Meri; Ylianttila, Lasse; Kautiainen, Hannu; Lakkala, Kaisa; Hannula, Henna-Reetta; Turunen, Esa; Viljakainen, Heli; Reunala, Timo; Snellman, Erna (2017)
    Humans obtain vitamin D from conversion of 7-dehydrocholesterol in the skin by ultraviolet B (UVB) radiation or from dietary sources. As the radiation level is insufficient in winter, vitamin D deficiency is common at higher latitudes. We assessed whether vernal solar UVB radiation at latitudes 61 degrees N and 67 degrees N in Finland has an impact on serum 25-hydroxyvitamin D [S-25(OH) D] concentrations. Twenty-seven healthy volunteers participated in outdoor activities in snow-covered terrain for 4-10 days in March or April, with their face and hands sun-exposed. The personal UVB doses and S-25(OH) D levels were monitored. A mean UVB dose of 11.8 standard erythema doses (SED) was received during an average of 12.3 outdoor hours. The mean S-25(OH) D concentration in subjects with a baseline concentration below 90.0 nmol/L (n=13) increased significantly, by 6.0 nmol/L from an initial mean of 62.4 nmol/L (p
  • Karhu, Piia (Helsingin yliopisto, 2022)
    Background. To achieve healthier diets and to support the transition towards more sustainable food systems, animal protein needs to be replaced with plant-based protein sources as suggested by the EAT-Lancet commission. However, plant-based diets may be harmful to bone health due to lower intakes of vitamin D and calcium. Additionally, whether the different amino acid profiles of plant and animal proteins contribute to bone health has not been addressed. Objectives. The aim was to investigate whether partial replacement of red and processed meat with legumes affects bone turnover and whether the intake of individual amino acids from diverse sources play a role in this relationship. In addition, the intake of nutrients important for bone health such as vitamin D and calcium were examined. Materials and methods. The study was a six-week partly controlled randomized clinical trial carried out in a parallel design. 102 healthy men aged 20 – 65 years were stratified into two groups. The meat group consumed 760 g of boneless and cooked red and processed meat per week corresponding to 25 % of the total protein intake. The legume group consumed legume-based products corresponding to 20 % of the total protein intake and 200 g of red and processed meat per week corresponding to 5% of total protein intake. The rest of the diet was not controlled. Bone turnover and mineral metabolism markers were analyzed from the blood samples. Analysis of covariance (adjust for baseline values) was used to analyze the differences between the groups. Nutrient intake was recorded with 4-day food records and analyzed with t-test. Intakes of protein, amino acids, and bone-related nutrients were of interest. Results. No differences in bone formation (bone-specific alkaline phosphatase) or bone resorption markers (tartrate-resistant acid phosphatase 5b) were observed between the diet groups (P=0.875 and P=0.95). Neither parathyroid hormone, 25-hydroxyvitamin D, calcium, or phosphate concentrations differed between the groups (P=0.32, P=0.32, P=0.826, P=0.32, respectively). Parathyroid hormone concentrations increased (meat P=0.006; legume P< 0.001) and 25-hydroxyvitamin D concentrations decreased significantly in both groups (meat P=0.043; legume P=0.018). Protein, calcium, and vitamin D intakes did not differ between the groups at the endpoint (P=0.276, P=0.271 P=0.840, respectively). Regarding individual amino acids, methionine intake was higher in the meat group (P=0.041) whereas the legume group had higher intakes of arginine (P< 0.001), asparagine and aspartic acid (P=0.001), glutamine and glutamic acid (P=0.008), leucine (P=0.045) phenylalanine (P=0.001), proline (P=0.015), serine (P=0.046) and tyrosine (P=0.029). Mean intakes of nutrients and essential amino acids in both groups were met the recommendations. Conclusions: Our results suggest that increasing the proportion of plant-based protein by replacing red and processed meat in the diet does not cause a risk for bone health and provides adequate amounts of essential amino acids and nutrients. However, it seems that in the present study differing amino acid intakes did not contribute to bone turnover.
  • Säilä, Pasi (Helsingfors universitet, 2016)
    Oxysterols and vitamin D related compounds are found to be biologically active in brain. They might be involved in different psychiatric and neurodegenerative diseases. These compounds have traditionally been analysed from tissues using somewhat laborious and time-consuming gas chromatograpy and liquid chromatography mass spectrometric methods. To the side of these methods ambient desorption ionization methods have been developed. The advantage of these methods is rapid and easy operation. Usually minimal or no sample pretreatment is required. In addition these methods can be applied to imaging of for example tissues. The aim of this work was to study if it is possible to detect certain oxysterols and vitamin D related compounds from rat brain tissue samples with desorption atmospheric pressure photoionization (DAPPI). The compounds chosen to this study were cholesterol, vitamin D3, 25-hydroxyvitamin D3, 7-dehydrocholesterol, desmosterol and 7-ketocholesterol. DAPPI is especially suitable for efficient ionization of this kind of neutral and non-polar compounds. Detected MS and MSn spectras of the brain tissue samples were compared to those obtained from standard compounds. As a result we could not detect vitamin D3, 25-hydroxyvitamin D3, 7-dehydrocholesterol, desmosterol from rat brain samples with DAPPI. Excluding vitamin D3 it is possible that those other analytes are present at the spectras of brain samples but there is some other compound with same mass which makes the reliable identification of studied compounds impossible. 7-ketocholesterol and cholesterol were the only compunds we detected from brain tissue sections. 7-ketocholesterol can be formed via auto-oxidation in samples containing excess amount of cholesterol. According to this study it is impossible to say if the detected 7-ketocholesterol is formed endogenously or during sample preparation and analysis.
  • Lamberg-Allardt, Christel; Brustad, Magritt; Meyer, Haakon E.; Steingrimsdottir, Laufey (2013)
  • 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.