Effect of vitamin C on lipoproteins in healthy adults.

BACKGROUND

It has been suggested that vitamin C can modify the composition of lipoproteins in healthy subjects.

OBJECTIVE

To determine the possible modification of lipid levels in the presence of vitamin C, and the effect of various doses on lipid levels.

DESIGN

This is a sequential open clinical trial, where the same individuals are used as their own controls, and where the same observer at random administers 1 or 2 g of oral vitamin C during a month, followed by a further month without treatment.

PATIENTS: 124 healthy volunteers of both sexes, between 17 and 74 years of age, whose lifestyle was not modified during the study.

MEASUREMENT: At the beginning of the study a determination was made of lipid levels, risk factors such as age, physical activity, tobacco and alcohol use, weight and arterial pressure; at the end of the first month during vitamin C therapy, and again at the end of the second month without therapy, lipid levels were determined, namely, TG, TC, HDL-C, HDL2-C, HDL3-C, LDL-C, ApoA1, ApoB and Lp(a).

RESULTS

After one month of treatment with 2 grams of vitamin C, a significant decrease of ApoB was observed, namely, 5.5% in females and 8% in males (p = 0.019). Vitamin C treatment shows the following differential data: a negative correlation of Lp(a) with HDL3-C, in both sexes; in males, the positive correlation of age with LDL-C and the negative correlation of tobacco with HDL-C disappear, positive correlations appear between physical activity and HDL-C, between tobacco and LDL-C, between weight and ApoB, between SBP and TG, and between DBP and ApoB; in females, the positive correlation between weight and TG, and the negative correlation between weight and HDL-C both disappear, negative correlations appear between physical activity and both TC and ApoB, between weight and HDL3-C, a positive correlation appears between DBP and HDL2-C. Compared to non-drinkers, in males who consume less than 50 grams of alcohol daily, vitamin C produces a significant decrease in DHL3-C, while the significant increase in Lp(a) disappears.

CONCLUSIONS

From the results in the follow-up of this group of healthy individuals, it can be deduced that vitamin C produces a decrease in ApoB in both sexes where 2 g are administered daily. When the risk factors are correlated, the results vary substantially, particularly with reference to the sex of the individuals. Women benefit much more than men from vitamin C therapy, especially when physical activity, weight and diastolic blood pressure are considered. Compared to non-drinkers, male drinkers demonstrate a decrease in HDL3-C, and the significant increase in Lp(a) disappears.