Beetroot juice nitrate levels in fingertip blood versus venous blood
What it found
In 10 young adults, nitrate and nitrite levels in fingertip blood were higher than in venous blood after drinking beetroot juice, but the two were strongly linked.
Fingertip blood may be a practical stand-in for lab blood tests.
What they found
Studies in people
Baseline levels similar
Before drinking beetroot juice, nitrate and nitrite levels were similar in fingertip serum and venous plasma.
Higher after beetroot
After drinking beetroot juice, fingertip serum had higher nitrate and nitrite levels than venous plasma at all time points measured.
Strong correlation
Nitrate and nitrite levels in fingertip serum were strongly linked to levels in venous plasma across the post-drink period, except for nitrate at 2 and 4 hours after drinking.
Overestimation range
Fingertip serum nitrate was 125 to 141 percent of venous values, and nitrite was 156 to 183 percent of venous values after beetroot juice.
Nitrate less precise
The authors note that fingertip nitrate assessment may be less precise than nitrite assessment.
What the authors conclude
“We show that although fingertip serum [NO32] and [NO22] overestimate those measured by venous plasma after dietary NO32 intake (125–141% and 156–183% of venous values), [NO32] and [NO22] in fingertip serum samples may be utilized for assessing blood [NO32] and [NO22] levels, although [NO32] assessment may lack precision compared to [NO22].”
Also in their conclusions
- They conclude that fingertip serum nitrate and nitrite may be used to assess blood levels, though nitrate assessment may be less precise than nitrite.
- They suggest that fingertip sampling could allow monitoring outside labs and help understand the benefits of dietary nitrate.
How it was done
The authors wanted to see if a simple fingertip blood test could replace venous blood draws for tracking nitrate and nitrite levels, which may help people monitor the benefits of dietary nitrate for health and exercise.
Ten healthy young adults drank 140 mL of nitrate-rich beetroot juice. Fingertip serum and venous plasma samples were collected before and every hour for up to 4 hours after drinking.
What it can’t tell you
- This was a small study of 10 young, healthy adults, so results may not apply to other groups.
- The study did not test whether fingertip monitoring leads to better health or exercise outcomes.
The paper
- Title
- Nitrate and Nitrite Concentrations in Fingertip Serum Following Beetroot Juice Ingestion Correlate with Those in Venous Plasma
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Fujii N, Omori S, Kataoka Y, Nishiyasu T, Omi N (2024). Nitrate and Nitrite Concentrations in Fingertip Serum Following Beetroot Juice Ingestion Correlate with Those in Venous Plasma. Journal of nutritional science and vitaminology. doi:10.3177/jnsv.70.441Free full textPubMed 39477482DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error