Riboflavin (vitamin B-2) and health

Abstract Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for vitamin K. In this Opinion, the Panel considers vitamin K to comprise both phylloquinone and menaquinones. The Panel considers that none of the biomarkers of vitamin K intake or status is suitable by itself to derive DRVs for vitamin K. Several health outcomes possibly associated with vitamin K intake were also considered but data could not be used to establish DRVs. The Panel considers that average requirements and population reference intakes for vitamin K cannot be derived for adults, infants and children, and therefore sets adequate intakes (AIs). The Panel considers that available evidence on occurrence, absorption, function and content in the body or organs of menaquinones is insufficient, and, therefore, sets AIs for phylloquinone only. Having assessed additional evidence available since 1993 in particular related to biomarkers, intake data and the factorial approach, which all are associated with considerable uncertainties, the Panel maintains the reference value proposed by the Scientific Committee for Food (SCF) in 1993. An AI of 1 μg phylloquinone/kg body weight per day is set for all age and sex population groups. Considering the respective reference body weights, AIs for phylloquinone are set at 70 μg/day for all adults including pregnant and lactating women, at 10 μg/day for infants aged 7–11 months, and between 12 μg/day for children aged 1–3 years and 65 μg/day for children aged 15–17 years.

https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2017.4780

Dietary reference values for vitamin K.

Effect of physical activity on thiamine, riboflavin, and vitamin B-6 requirements.

http://www.tara.tcd.ie/bitstream/handle/2262/34591/Impaired%20functioning%20of%20thermolabile%20methylenetetrahydrofolate%20reductase%20is%20dependent%20on%20riboflavin%20status%20-%20implications%20for%20riboflavin%20requirements.pdf;sequence=1

Impaired functioning of thermolabile methylenetetrahydrofolate reductase is dependent on riboflavin status: implications for riboflavin requirements

Randomized controlled trial of homocysteine-lowering vitamin treatment in elderly patients with vascular disease

Riboflavin and vitamin B-6 intakes and status and biochemical response to riboflavin supplementation in free-living elderly people.

Spiro-OMeTAD has become a ubiquitous hole-transporting material (HTM) in perovskite-based solar cells. However, it has several intrinsic drawbacks including its long-term stability, low conductivity and hole-mobility. Hence, the synthesis of new derivatives with improved charge transporting properties remains an important goal. Here, we have devised a novel synthetic route to prepare unsymmetrically functionalised Spiro-OMeTAD derivatives. We report the synthesis of a mono-demethylated Spiro-OMeTAD derivative, SOT-OH , utilising two different synthetic protocols and show two new derivatives, a dimer ( SOT-D ) and a trimer ( SOT-T ) as exemplars. We fully characterise the developed materials and show significantly higher conductivity values than Spiro-OMeTAD when doped with standard ionic salts at the same concentrations. The solar cells fabricated using the mixed composition Cs 0.05 Ĳ FA 0.85 MA 0.15 ) 0.95 PbI 3 perovskite and the novel SOT-D show power conversion efficiencies of up to 16.4% under standard AM1.5 illumination compared to 16.1% observed when using the benchmark Spiro-OMeTAD . have designed methodology to reliably and conveniently synthesise a new asymmetric Spiro-OMeTAD building block ( SOT-OH ) using both top-down and bottom-up procedures. As exemplars, we have synthesised a dimer ( SOT-D ) and a trimer ( SOT-T ) from SOT-OH and have shown that these materials have higher conductivities, and in the case of SOT-D a higher power conversion efficiency, than Spiro-OMeTAD , which we attribute to the more porous morphology of their films. This work not only provides new methodology for creating unsymmetrically functionalised Spiro-OMeTAD derivatives, which will allow exciting new HTMs to be prepared for perovskite and solid-state dye-sensitised solar cells, but also indicates that a more porous HTM film architecture may be advantageous in developing better performing devices.

F Tracey

Papers

Riboflavin and vitamin B-6 intakes and status and biochemical response to riboflavin supplementation in free-living elderly people.

Synthesis of SOT-OH and its application as a building block for the synthesis of new dimeric and trimeric Spiro-OMeTAD materials †

Synthesis of SOT-OH as a building block for the synthesis of new dimeric and trimeric Spiro-OMeTAD Materials