Is vitamin C related to weight? Weight exceeding this range is the key!

We often say "an apple a day keeps the doctor away". This is because apples are rich in vitamin C and other nutrients. Eating the right amount of fruit every day helps to balance nutrition and prevent diseases.

But in fact, different groups of people have different needs for vitamin C, and the amount of food intake should vary from person to person. For example, the "Chinese Dietary Nutrient Reference Intake (2013)" recommends that the recommended daily intake of vitamin C for normal adults is 100 mg, and the daily intake for preventing non-communicable chronic diseases is 200 mg. People with certain diseases, pregnant women and nursing mothers should increase their intake of vitamin C.

Moreover, many studies have pointed out that being overweight may have a negative impact on the status of plasma vitamin C. So do people of different weights have the same requirements for vitamin C?

Recently, a study published in the journal Nutrients pointed out that obese people may need to consume more vitamin C. According to the researchers' estimate, within the weight range of 60 kg to 90 kg, for every 10 kg increase in weight, an additional 10 mg of vitamin C is needed per day to have similar plasma vitamin C concentrations as lighter people.

Screenshot source: Nutrients

In order to preliminarily investigate how much additional vitamin C is needed in people with higher body weight to achieve a similar vitamin C status as people with lower body weight, the researchers analyzed data from two other studies. In the first study, the researchers included a total of 68 healthy men, who had to go through two phases during the trial. The first phase was a vitamin C depletion phase, during which the researchers restricted the participants' daily dietary vitamin C intake. The second phase was a supplementation phase, in which the researchers gave supplemental vitamin C based on the participants' weight. In the second study, the researchers included a total of 7 healthy men, who underwent similar vitamin C depletion and supplementation phases in the hospital for 4 to 6 months.

The researchers found that after restricting the participants' vitamin C intake, the average plasma ascorbic acid concentration of the participants was about 13 µmol/L, and after supplementing with 117 mg of vitamin C per day, the average plasma concentration of the participants was about 49 µmol/L. After further analysis based on the different weights of the participants and the plasma vitamin C concentrations of the participants after vitamin C supplementation, the researchers found that:

The difference in plasma vitamin C concentrations between participants with the lowest and highest body weights was 18 µmol/L;

The difference in vitamin C intake between participants with the lowest and highest plasma vitamin C concentrations was 32 mg/day.

A 91 kg person would need to consume an additional 32 mg of vitamin C (approximately 140 mg/day) to have the same plasma vitamin C concentration as a 59 kg person who consumes 109 mg of vitamin C per day.

▲There is a linear negative correlation between the participants' weight and changes in plasma vitamin C concentration. (A) However, when the body weight exceeds 90 kg, the required increase in vitamin C intake is nonlinearly related to body weight. (B) (Image source: Reference [1])

The paper concluded that within the range of about 60 kg to 90 kg, an additional 10 mg of vitamin C is needed per day for every 10 kg increase in weight. In other words, a person weighing 90 kg needs to consume about 140 mg of vitamin C per day to have a similar plasma vitamin C concentration as a 60 kg person who consumes 110 mg of vitamin C per day. However, when the weight exceeds 90 kg and approaches 120 kg, this vitamin C requirement will gradually decrease.

This may be due to the fact that, with increasing obesity and fat mass, low-grade inflammation mediated by adipokines and oxidative stress also increases. Since conditions of inflammation and oxidative stress are generally thought to increase the turnover of vitamin C, a further increase in vitamin C intake would be required to compensate for obesity. However, vitamin C is a water-soluble molecule and its volume of distribution is unlikely to increase in proportion to increasing adiposity.

The paper points out that in addition to body weight, there are other factors that affect vitamin C status. For example, the basic concentration of vitamin C in the body, smoking status, gender, emotional stress, physical activity and other factors. When giving advice, in addition to referring to the recommended daily intake, it is recommended to consider other factors. It is recommended that overweight and obese people eat more fruits and vegetables.

References

[1] Carr AC, Block G, Lykkesfeldt J. Estimation of Vitamin C Intake Requirements Based on Body Weight: Implications for Obesity. Nutrients. 2022; 14(7):1460. https://doi.org/10.3390/nu14071460