Phylloquinone as a biochemical marker for the dietary intake of green leafy vegetables by the K'ekchi people of Alta Verapaz, Guatemala

Vitamin K₁ (phylloquinone) was examined as a potential biochemical marker of indigenous leafy green vegetable intake. Phylloquinone content for 13 species of indigenous leafy green vegetables currently consumed by the K'ekchi‐speaking people of Alta Verapaz, Guatemala, ranged from 0.20–1.14 mg/100 g fresh weight for raw samples (n = 25), and from 0.27–1.51 mg/100 g fresh weight for cooked samples (n = 14) as determined by reversed‐phase high‐performance liquid chromatog‐raphy. Fasting plasma phylloquinone concentrations in a sample of K'ekchi‐speaking women (n = 26) who participated in a dietary survey that estimated the frequency of intake of leafy green vegetables ranged from 0.19–2.01 nmol/L (x = 0.79 nmol/L). When ranked plasma phylloquinone values were compared to the ranked average 7‐day intake of indigenous greens, there was no correlation between the two ranks (p = 0.2157).

Key words:

• Phylloquinone
• biochemical marker
• traditional processing
• leafy vegetables
• 7‐day food frequency questionnaire
• Guatemala