Table 1

Summary of previous findings regarding within-individual variation of serum concentrations of carotenoids, retinol, α-tocopherol, and ascorbic acid

Ref. no. of the study
2345678910311
Period of studyDayDay2 wk2 wkMenstrual cycleMenstrual cycleSeason 6 moSeason 5–9 moSeason 12 mo1 yr22 yrs
Index of variationCVaCVCCCCCCCVCVICCDifferenceCVCVPMC
No. of subjects15332323301292661829442
α-Carotene0.090.950.090.010.470.31
β-Carotene0.060.080.920.050.040.81b50%0.360.200.43
Cryptoxanthin0.080.910.060.370.20
Lutein/zeaxanthin0.090.590.100.050.290.18
Lycopene0.890.060.050.430.18
Total carotenoids0.680.04
Retinol0.040.810.050.700.14
α-Tocopherol0.050.57cNo difference0.110.47
Ascorbic acid0.290.22
  • a CV, coefficient of variation; CCC, concordance correlation coefficient; ICC, intraclass correlation coefficient; PMC, product-moment correlation coefficient.

  • b α- and β-carotene.

  • c α- and γ-tocopherol.