Vitamin C Concentration of Plasma and Leukocytes as Related to Smoking Habit, Age, and Sex of Humans

Brook, M.; Grimshaw, J. J.

doi:10.1093/ajcn/21.11.1254

Cited by 115 publications

(32 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Several lifestyle factors have been postulated as predictors of serum β-carotene and/or serum ascorbic acid concentrations, i.e., sex, smoking, alcohol intake, HDL cholesterol, and dietary intakes of β-carotene or vitamin C. 11,13,[16][17][18][19][20] However, in this study, neither sex, alcohol intake, cigarette consumption, nor HDL cholesterol significantly correlated with the change in serum β-carotene or Table III ascorbic acid after the level of supplementation and the concentration at baseline were controlled for, with the sole exception of cigarette consumption (Table III). This may be due to the small number of study subjects.…”

Section: Discussionmentioning

confidence: 99%

Effects of Three‐month Oral Supplementation of β‐Carotene and Vitamin C on Serum Concentrations of Carotenoids and Vitamins in Middle‐aged Subjects: A Pilot Study for a Randomized Controlled Trial to Prevent Gastric Cancer in High‐risk Japanese Population

Sasaki

Tsubono

Okubo

et al. 2000

Japanese Journal of Cancer Research

View full text Add to dashboard Cite

Prior to a randomized controlled trial to prevent gastric cancer by oral supplementation of β β β β-carotene and vitamin C in a high-risk Japanese population, we examined the serum response to threemonth oral supplementation of β β β β-carotene (0, 3, 30 mg/day) and vitamin C (0, 50, 1000 mg/day) by a three-by-three factorial design using 54 subjects (age range = = = =40-69 years). Serum concentrations of carotenoids, α α α α-tocopherol, and ascorbic acid were examined at baseline, and one, two, and threemonth points. Both serum β β β β-carotene and ascorbic acid were significantly higher in high-dose groups than in each placebo group during the supplementation. The serum β β β β-carotene increased gradually (597-830% increase) during the study, whereas the serum ascorbic acid reached nearly a steady-state at the one-month point and remained stable thereafter (88-95% increase). No statistically significant interaction between β β β β-carotene and vitamin C supplementations was observed either for serum β β β β-carotene or for serum ascorbic acid. Among carotenoids and α α α α-tocopherol examined, serum lycopene in the high-dose β β β β-carotene group was significantly higher than in the placebo group at all points. No unfavorable change in carotenoids and α α α α-tocopherol was observed in any group.Key words: β-Carotene -Ascorbic acid -Supplements -Nutrient -Randomized controlled trial Gastric cancer has long been the most common cancer in Japan.1) Several epidemiologic studies have reported protective effects of high intake of β-carotene and vitamin C (ascorbic acid) and their high serum or plasma concentration levels against gastric cancer.2, 3) Vitamin C in fruits and vegetables is considered to be a preventative substance inhibiting nitrosamine formation and also acting as a free radical scavenger.2, 4) Atrophic gastritis is considered to be a precursor of intestinal-type gastric cancer. 5) A protective effect of β-carotene against the progression of atrophic gastritis has been reported. 6)Based on these findings, we planned a randomized controlled trial to test the preventative effect of oral β-carotene and vitamin C supplementation for a high-risk population, i.e., subjects with atrophic gastritis. 7) However, the effects of oral supplementation of β-carotene and vitamin C on the serum concentrations have not yet been established in Japanese populations. Prior to the study, we conducted a pilot study using subjects of a health check-up program to evaluate the effect of supplementation of β-carotene and vitamin C on the serum levels. 8) MATERIALS AND METHODS Study designThe study design has been reported elsewhere.8) Briefly, the subjects were recipients of a health check-up program in a local general hospital with chronic atrophic gastritis diagnosed on the basis of pepsinogen I less than 70 mg/ml and pepsinogen I/pepsinogen II ratio less then 3.0. The age ranged from 40 to 69 years. Among 90 subjects screened, 55 subjects, 35 men and 20 women, participated in the trial. The participants were randomly ass...

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of Three‐month Oral Supplementation of β‐Carotene and Vitamin C on Serum Concentrations of Carotenoids and Vitamins in Middle‐aged Subjects: A Pilot Study for a Randomized Controlled Trial to Prevent Gastric Cancer in High‐risk Japanese Population

Sasaki

Tsubono

Okubo

et al. 2000

Japanese Journal of Cancer Research

View full text Add to dashboard Cite

show abstract

“…As to the possible cause for influences of sex in vitamin C status, Morgan et al (1955), Loh and Wilson (1971), and Schorah (1981) have suggested that there is a difference in the metabolism of ascorbic acid between males and females. Brook and Grimshaw (1968), however, have stated it is not attributable to ovarian hormone activity, since the sex difference in vitamin C status persists in old age. Schorah (1981) has presented that the differences between males and females disappear as plasma levels fall.…”

Section: Correlationsmentioning

confidence: 99%

“…Morgan et al (1955) have observed that females maintained higher serum levels of vitamin C on lower intakes than males. In addition, Brook and Grimshaw (1968) and Attwood et al (1978) have also pointed out that the lower vitamin C concentration found in the plasma or leukocytes of the males as compared with that of the females are not solely due to dietary variations. A definite sex difference in the level of serum ascorbic acid appears to exist regardless of dietary habits.…”

Section: Correlationsmentioning

confidence: 99%

“…Morgan et al (1955), Brook and Grimshaw (1968), Burr et al (1974), Pelletier (1975), Attwood et al (1978) and Bates et al (1979) have reported that the value of vitamin C in plasma and leukocytes is higher in females than in males, and the difference persists into old age. Loh and Wilson (1971) have shown that below the age of 60, the females have higher ascorbic acid values than the males, but after this age, the male concentrations exceed those in females.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Influences of sex and age on serum ascorbic acid.

Sasaki

Kurokawa

Kobayasi

et al. 1983

Tohoku J. Exp. Med.

View full text Add to dashboard Cite

“…Research has also shown that smokers have low levels of vitamin C (12,13). A possible explanation for this effect is that smokers absorb less vitamin C from the gut than non-smokers.…”

mentioning

confidence: 99%