Vitamin C is an essential nutrient in humans and must be obtained through the diet. The
aim of this study was to determine vitamin C uptake in healthy volunteers after consuming
kiwifruit (Actinidia chinensis var. Hort. 16A), and to
determine the amount of fruit required to raise plasma vitamin C to ‘healthy’ (i.e.
>50 µmol/l) and ‘optimal’ or saturating levels (i.e. >70 µmol/l). Leucocyte
and urinary vitamin C levels were also determined. A total of fifteen male university
students with below average levels of plasma vitamin C were selected for the study. Weekly
fasting blood samples were obtained for a 4-week lead-in period and following
supplementation with, sequentially, half, one, two and three Gold kiwifruit per d for 4–6
weeks each, followed by a final 4-week washout period. The results showed that addition of
as little as half a kiwifruit per d resulted in a significant increase in plasma vitamin
C. However, one kiwifruit per d was required to reach what is considered healthy levels.
Increasing the dose of kiwifruit to two per d resulted in further increases in plasma
vitamin C levels as well as increased urinary output of the vitamin, indicating that
plasma levels were saturating at this dosage. Dividing the participants into high and low
vitamin C groups based on their baseline plasma and leucocyte vitamin C levels
demonstrated that it is critical to obtain a study population with low initial levels of
the vitamin in order to ascertain a consistent effect of supplementation.
Respiration and mitochondrial content alter over gestation/with labour. Decreased respiration at 11 weeks and increased mitochondrial content at 12-13 weeks may relate to onset of maternal blood flow, and increased respiration as a result of labour may be an adaptation to ischaemia-reperfusion. At term, mitochondria were more susceptible to changes in respiratory function relative to first trimester when cultured in vitro, perhaps reflecting changes in metabolic demands as gestation progresses. Metabolic plasticity of placental mitochondria has relevance to placenta-mediated diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.