Vitamin C Associated With Lower BMI & Body Fat Levels
A shortage of vitamin C is associated with high body fat levels due to a reduction in the bodies ability to burn stored fat for energy according to the findings of several recent studies.
One such study, published in the Journal of Nutrition in July 2007, looked at the levels of Vitamin C in the blood of a group of 118 middle aged individuals. The researchers found that the heavier individuals tended to have lower levels of vitamin C in the blood. The average vitamin C level of the participants with a BMI lower than 25 was 54.4umol/L compared to just 37.2umol/L for individuals with a BMI greater than 35.
The researchers also found that both body fat percentage and waist circumference were inversely correlated with plasma vitamin C levels.
Vitamin C is a key component in the production of carnitine in the body. Carnitine is involved in the fat oxidation process where fatty acids are broken down into energy usable by the body. During exercise in particular, a shortage of carnitine can reduce the bodies abilility to utilise fat for energy resulting in increased fatigue and a decrease in physical performance.
A study, published in the Journal of the American College of Nutrition in 2005, found that individuals who received an adequate intake of vitamin C oxidized 30% more fat during moderate exercise than individuals who were deficient in vitamin C.
A further study, published in the journal Nutrition & Metabolism, found that individuals with low vitamin C levels (<34umol/L) oxidized 25% less fat per kilogram of body weight during exercise compared to individuals with adequate vitamin C levels (>34umol/L). Furthermore, the individuals with low vitamin C levels reported a greater degree of fatigue during the exercise regime.
When some of the low vitamin C group were put on a vitamin C intervention of 500mg per day over four weeks, fat oxidization during exercise increased by 300% compared to the individuals who were not put on the intervention.
The authors concluded that “Low vitamin C status may partially explain the inverse relationship between vitamin C status and adiposity and why some individuals are unsuccessful in their weight loss attempts.”
Vitamin C is added to many food products and is found in a large number of fruits and vegetables. Despite this, it is believed that as many as 20% of adult Americans are deficient in the vitamin. The recommended daily intake of vitamin C lies between 70 and 90mg per day however many health organizations advocate much higher doses than this. The Linus Pauling institute, an organization dedicated to micro-nutrient research recommends 400mg of vitamin C per day. Vitamin C is well tolerated by the body and no adverse have been noted in levels up to 2g per day.
Vitamin C has a relatively short half life of 30 minutes meaning that it needs to be consumed at regular intervals for its effects to be maintained. Vitamin C should be taken around an hour before exercise in order to get the greatest benefit in terms of fat oxidization.
