====== Vitamin D ====== ===== Bildung im Körper ===== > Demnach reicht es auch in Deutschland, das sich von Breitengrad 47 bis 55 N° erstreckt, für ungefähr die Hälfte des Jahres für Erwachsene aus, pro Tag ein Viertel der Körperoberfläche (Gesicht, Hände und Teile von Armen und Beinen) je nach Hauttyp und Jahreszeit 5 bis 25 Minuten der Sonne auszusetzen. Quelle: http://www.bfr.bund.de/de/ausgewaehlte_fragen_und_antworten_zu_vitamin_d-131898.html ===== Überdosierung ===== Mehr als 100μg/Tag sollten nicht eingenommen werden. Quelle: https://www.netdoktor.de/ernaehrung/vitamin-d/ueberdosierung/ > Im Falle der zusätzlichen Aufnahme von Vitamin D über Vitamin D-Präparate ist zu berücksichtigen, dass die Europäische Behörde für Lebensmittelsicherheit (EFSA) für Erwachsene und für Kinder ab 11 Lebensjahren eine tolerierbare Gesamtzufuhrmenge pro Tag von 100 Mikrogramm Vita­min D und für Kinder bis 10 Lebensjahre von 50 Mikrogramm Vitamin D abgeleitet hat. Quelle: http://www.bfr.bund.de/de/ausgewaehlte_fragen_und_antworten_zu_vitamin_d-131898.html ===== DGE Empfehlung ===== Die //Deutsche Gesellschaft für Ernährung// empfiehlt die Einnahme von 20μg/Tag Vitamin D ab dem ersten Lebensjahr. Das schließt Vitamin D aus normaler Nahrung bereits ein. Quelle: http://www.dge.de/wissenschaft/referenzwerte/vitamin-d/ ===== SACN Vitamin D and Health report ===== Das //Scientific Advisory Committee on Nutrition// hat 2016 folgende Empfehlung herausgegeben: {{allgemin:sacnvitamindandhealthreport2016.pdf|SACN Vitamin D And Health Report 2016.pdf}} Original: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/537616/SACN_Vitamin_D_and_Health_report.pdf === Empfehlung === Altersunabhängig ab Geburt 10μg/Tag Vitamin D Einnahme in Wintermonaten (Oktober bis März). === Auszüge === * //RNI// = Reference Nutrient Intakes * //DRV// = Dietary Reference Values * //RCT// = randomised controlled trial > The small amount of UVB radiation in winter sunlight is insufficient to initiate synthesis of any biologically relevant amounts of vitamin D. > Sunlight-induced vitamin D synthesis in white-skinned populations becomes effective from late March/early April with maximum concentrations observed in September after a summer of exposure. Serum 25(OH)D concentration decreases from October onwards throughout the winter months. > The pigment melanin absorbs so me of the UVB radiation which would otherwise be absorbed by 7-DHC. This means that if the absolute dose of UVB radiation is the same as that given to a person with white skin then people with dark skin will synthesise less. However, darker skin has the same capacity to synthesise vitamin D if the dose of radiation is adjusted for the protective effect of melanin. > Cohort studies suggest an association between increased serum 25(OH)D concentration and decreased fracture risk in adults ≥50y; evidence from RCTs, however, suggests vitamin D plus calcium supplementation is more effective than vitamin D alone in reducing fracture risk. On balance, vitamin D supplements alone appear to have no effect on fracture risk in older men and women. > Evidence from RCTs suggest that vitamin D supplementation may improve muscle strength and function in adults <50y with mean serum 25(OH)D concentration <30nmol/L. > Previously in the UK, an RNI (but not an EAR or LRNI) for vitamin D was set only for population groups at high risk of deficiency (DH, 1991). It was assumed that, for most people, the amount of vitamin D produced by exposure to sunlight containing UVB in the summer months would be adequate for achieving serum 25(OH)D concentrations ≥25nmol/L during winter. It is now known that this is not the case. > An RNI of 10μg/d (400IU/d) is recommended for the general UK population aged 11y and above. > ... > This is the average amount needed to achieve a serum 25(OH)D concentration ≥25nmol/L during winter in 97.5% of the population. > Data from the modelling exercise were therefore extrapolated to younger age groups and the RNI of 10μg/d (400IU) recommended for the UK population was considered appropriate for children aged 4 up to 11y. > Since data are not available to clearly relate serum 25(OH)D concentration in the infant to current or long term health, //Safe Intakes// rather than //RNIs// are recommended for infants and children aged up to 4y. > //Safe Intakes// are based on a precautionary approach and reflect the insecurities of the data. > A //Safe Intake// range of 8.5-10μg/d (340-400 IU), based on concentrations of vitamin D in infant formula, is recommended for infants aged 0-11m. > There is currently no vitamin D RNI for exclusively breastfed infants because it was previously assumed that maternal vitamin D supplementation during pregnancy and then breast milk would provide the infant with adequate vitamin D for the period of exclusive breast feeding. The few available data suggest that it is unlikely that an exclusively breastfed infant in the UK would maintain a serum 25(OH)D concentration ≥25nmol/L for 6 months. Therefore the //Safe Intake// range of 8.5-10μg/d (340-400IU) is recommended for all infants, including those who are exclusively breast fed and those who are breastfed and part-formula-fed, from birth. > A //Safe Intake// of 10μg/d (400IU), based on the RNI for the UK population, is recommended for infants and children aged 1-3y.