Background: Vitamin C may enhance nitric oxide (NO) production through stepwise reduction of dietary nitrate (NO 3) to nitrite (NO 2) to NO. The combined effect of vitamin C and NO 3 supplementation is relatively unexplored in untreated hypercholesterolemia. Aims: We aimed to examine whether co-administration of vitamin C and nitrate for 4-weeks would improve endothelial function (primary outcome), plasma NO metabolites, oxidative stress, and blood lipids (secondary outcomes). Methods: Subjects 50e70 years of age with low density lipoprotein (LDL) > 130 mg/dL and RHI 2 were enrolled in this randomized double-blind crossover study. Subjects were assigned to two 4-week supplementation treatments starting with 70 ml of concentrated beetroot juice (CBJ) with 1000 mg of vitamin C (NC) or CBJ with matched placebo (N), then switched to alternate treatment following 2-week washout. The change in reactive hyperemia index (RHI), sum of plasma NO metabolites (NO 2 þ NO 3 (NOx)), oxidized LDL (oxLDL), and serum lipids were assessed at baseline and at 4-weeks of each treatment period. Results: Eighteen subjects (11M:7F) completed all study visits. No significant treatment differences were observed in RHI change (N: 0.21 ± 0.12; NC: 0.20 ± 0.17; p ¼ 0.99). Secondary analysis revealed that a subgroup of NC subjects who started with a baseline RHI of <1.67 (threshold value for ED) had greater improvements in RHI compared to subjects with RHI >1.67 (1.23 ± 0.15 to 1.96 ± 0.19; n ¼ 8 vs. 1.75 ± 0.11 to 1.43 ± 0.10; n ¼ 8; p ¼ 0.02). Compared to N, NC experienced a significant increase in plasma NOx (N: 94.2 ± 15.5 mmol/L; NC: 128.7 ± 29.1 mmol/L; p ¼ 0.01). Although there was no significant difference in oxLDL change between treatments (N: À1.08 ± 9.8 U/L; NC: À6.07 ± 9.14 U/L; p ¼ 0.19), NC elicited significant reductions in LDL (N: 2.2 ± 2; NC: À10.7 ± 23; p ¼ 0.049), triglycerides (N: 14.6 ± 43; NC: À43.7 ± 45; p ¼ 0.03), and no change in serum high density lipoprotein. Within treatment group comparisons showed that only NC reduced oxLDL significantly from baseline to 4 weeks (p ¼ 0.01). Conclusions: No between intervention differences were observed in RHI. RHI only improved in NC subjects with ED at intervention baseline. Four weeks of NC enriched the NO pool and promoted reduction of blood lipids and oxidative stress in subjects with hypercholesterolemia. These preliminary findings highlight a supplementation strategy that may reduce the progression of atherosclerotic disease and deserves further attention in studies using flow mediated dilation methods. Clinical trial registration: www.clinicaltrials.gov (NCT04283630).

Objectives Dietary nitrate (NO3) plays an important role in human's physiological processes. Nutrition professionals (NPs) have a crucial role in increasing the awareness of NO3 benefits across various health and academic settings. The aim of this study was to assess the level of knowledge towards the NO3 effects among NPs in Jeddah, Saudi Arabia based on their qualifications and years of experience. Methods A cross-sectional study was conducted among NPs graduated or working in Clinical Nutrition Departments of health centers and two universities. A validated online questionnaire with a total of 12 questions assessed the dietary nitrate's knowledge with regards to its health effects, dietary sources, recommendations, biomarkers of intake, and metabolism. A Nitrate Knowledge Index (NKI) score (out of 23 points) was used to evaluate the responses. Results A total of 89 female NPs out of 144 successfully completed the questionnaire. Most of them aged ≤30 years (73%), possessed undergraduate degree (BS) (70.8%), and had an experience of ≤3 years of experience (73%). Overall, poor knowledge score was observed among NPs in most questions as the median was 10 (7) out of 23. The majority (64%) perceived the NO3 as beneficial. However, the most did not know its benefits in lowering the blood pressure (68.5%) and were unsure about the nitrate effects on cognitive function (60.7%), kidney function (57.3%) and cancer risk (48.3%) as well as the acceptable daily intake of nitrate (67.4%). Almost half of the NPs had insufficient knowledge of NO3 sources as they incorrectly identified bacon and sausage as high NO3 food. They also were unsure about the mechanisms involved in the conversion of nitrate into nitrite in the mouth (48.3%). Knowledge of factors that affect food NO3 content were generally good. No significant differences, (P &gt; 0.05), were observed in the median scores of NKI among the participants based on their level of education (BS: 8(6) vs. graduate degrees 10 (8.25)), nor based on years of experience (Experience ≤ 3 years: 10 (7) vs. &gt;3 years: 8.5 (6)). Conclusions The authors recommend developing and implementing educational programs to enhance the knowledge and beliefs towards NO3 among NPs, who work in clinical and academic settings. Funding Sources King Saud bin Abdulaziz University for Health Sciences.

Objectives Examine the effects of concentrated beetroot juice (CBJ) supplementation with and without vitamin C on markers of endothelial function (reactive hyperemia index (RHI) and blood biomarkers) and lipid profiles. Methods Subjects 50 to 70 years of age with low density lipoprotein (LDL) &gt; 130 mg/dL and RHI ≤ 2 were enrolled in this randomized crossover double-blind study. Two 4-week interventions were separated by a 2-week washout. Subjects were assigned to daily CBJ (70 mls) with 1000 mg of vitamin C (NC) or CBJ with matched placebo (N), then switched to alternate treatment. At baseline and 4-weeks, RHI was measured using EndoPAT. Secondary outcomes included the sum of plasma NO metabolites (NO2 + NO3 = NOx), oxidized LDL (oxLDL), and serum lipids. Paired t-tests were used to compare differences between treatments. Results Eighteen of 23 subjects completed all study visits (7 male, 11 females). No significant treatment differences were observed in RHI change (N: 0.21 ± 0.46; NC: 0.20 ± 0.67; P &gt; 0.05). NC subjects with baseline RHI of &lt; 1.67 (mean = 1.23; n = 8) had greater improvements in RHI compared to subjects with RHI scores &gt; 1.67 (mean = 1.75; n = 8; P = 0.02). Compared to N, NC resulted in a significant increase in plasma NOx (N: 94.2 ± 15.5 μmol/L; NC: 128.7 ± 29.1 μmol/L; P = 0.01). NC treatment reduced oxLDL/NOx ratio compared to N (N: −3.97 ± 2.8 U/L; NC: −4.29 ± 3.1 U/L; P = 0.02). NC elicited significant reductions in LDL (N: 2.2 ± 2; NC: −10.7 ± 23; P = 0.049), and triglycerides (N: 14.6 ± 43; NC: −43.7 ± 45; P = 0.03) with no change in serum high density lipoprotein. Conclusions NC appears effective at improving RHI in subjects with evidence of endothelial dysfunction. Four weeks of NC enriched the NO pool and promoted favorable changes in oxLDL/NOx ratio and blood lipids in subjects with hypercholesterolemia. These preliminary findings highlight a novel supplementation strategy that may reduce the progression of atherosclerotic disease and deserves further attention in studies using flow mediated dilation methods. Funding Sources Thornton Scholarship funds, College of Health Sciences, University of Kentucky.