Influence of vitamin A consumption on resting metabolic rate and fasting respiratory quotient in severely obese subjects.
OBJECTIVE
To study whether or not the amount of vitamin A consumed affects the resting metabolic rate (RMR) and fat oxidation at rest in severely obese subjects.


METHODS
In 239 obese subjects, RMR and fasting respiratory quotient (RQ) were determined by indirect calorimetry. Vitamin A consumption was calculated by the Czech PC program 'Nutrition'. The relation between the intake of vitamin A and RMR and RQ was tested by simple regression. High and low vitamin A consumers were defined by an upper and a lower quintile of vitamin A intake (>842 vs. <382 IU/day).


RESULTS
The RMR for high and low vitamin A consumers were 7,693.5 +/- 1,557 and 7,479.8 +/- 1,708 kJ/day, respectively, while the corresponding values for fasting RQ were 0.800 +/- 0.077 and 0.809 +/- 0.049, respectively. No significant correlation was found between vitamin A consumption and both RMR and RQ. Similarly, there was no significant difference in RMR and RQ, as well as weight, body mass index, body fat, waist girth and food quotient between the two groups characterized by high and low consumption of vitamin A. However, the energy intake of high vitamin A consumers was significantly higher than that of low vitamin A consumers, due to higher carbohydrate and protein intake.


CONCLUSIONS
There was no significant correlation between the vitamin A intake and RMR or RQ in obese subjects determined in this study.
Mikulová-Braunerová
Radka
R
Obesity Management Center, Third Department of Medicine, Charles University, Prague, Czech Republic. mikulova@email.cz
Hainer
Vojtech
V
Kunesová
Marie
M
Parízková
Jana
J
Slabá
Sárka
S
Wagenknecht
Martin
M
D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D001481:Basal Metabolism / Q000187:drug effects / Q000502:physiology*; D002153:Calorimetry, Indirect; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D002149:Energy Intake / Q000187:drug effects / Q000502:physiology; D005215:Fasting / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D014801:Vitamin A / Q000493:pharmacokinetics*
D014801:Vitamin A