Editing Vitamin C (section)

===Blood pressure===
Serum vitamin C was reported to be 15.13 μmol/L lower in people with [[hypertension]] compared to normotensives. The vitamin was inversely associated with both [[systolic blood pressure]] (SBP) and [[diastolic blood pressure]] (DBP).<ref name="pmid32426036">{{cite journal |vauthors=Ran L, Zhao W, Tan X, Wang H, Mizuno K, Takagi K, Zhao Y, Bu H |title=Association between serum vitamin C and the blood pressure: A systematic review and meta-analysis of observational studies |journal=Cardiovasc Ther |volume=2020 |issue= |pages=4940673 |date=April 2020 |pmid=32426036 |pmc=7211237 |doi=10.1155/2020/4940673 |url= | doi-access = free | title-link = doi }}</ref> Oral supplementation of the vitamin resulted in a very modest but statistically significant decrease in SBP in people with hypertension.<ref name=Guan2020>{{cite journal |vauthors=Guan Y, Dai P, Wang H |title=Effects of vitamin C supplementation on essential hypertension: A systematic review and meta-analysis |journal=Medicine (Baltimore) |volume=99 |issue=8 |pages=e19274 |date=February 2020 |pmid=32080138 |pmc=7034722 |doi=10.1097/MD.0000000000019274 |url=}}</ref><ref name=Llban2023>{{cite journal |vauthors=Lbban E, Kwon K, Ashor A, Stephan B, Idris I, Tsintzas K, Siervo M |title=Vitamin C supplementation showed greater effects on systolic blood pressure in hypertensive and diabetic patients: an updated systematic review and meta-analysis of randomized clinical trials |journal=Int J Food Sci Nutr |volume=74 |issue=8 |pages=814–25 |date=December 2023 |pmid=37791386 |doi=10.1080/09637486.2023.2264549 |s2cid=263621742 |url=https://figshare.com/articles/journal_contribution/24241426 |access-date=December 23, 2023 |archive-date=January 21, 2024 |archive-url=https://web.archive.org/web/20240121044305/https://figshare.com/articles/journal_contribution/Vitamin_C_supplementation_showed_greater_effects_on_systolic_blood_pressure_in_hypertensive_and_diabetic_patients_an_updated_systematic_review_and_meta-analysis_of_randomised_clinical_trials/24241426 |url-status=live }}</ref> The proposed explanation is that vitamin C increases intracellular concentrations of [[tetrahydrobiopterin]], an endothelial [[nitric oxide synthase]] cofactor that promotes the production of [[nitric oxide]], which is a potent vasodilator. Vitamin C supplementation might also reverse the nitric oxide synthase inhibitor [[NG-monomethyl-L-arginine|NG-monomethyl-L-arginine 1]], and there is also evidence cited that vitamin C directly enhances the biological activity of nitric oxide<ref name=Guan2020 />