Vitamin C augments concentration of alpha-tocopherol in cystic fibrosis

Among adults with cystic fibrosis, vitamin C decreased the plasma disappearance rate of alpha-tocopherol, thereby augmenting its concentrations, according to a study published in Nutrients.

In an Oregon State University press release, Maret G. Traber, PhD, a study investigator with the school, explained that in addition to oxidative stress, cystic fibrosis is also characterized by problems with fat absorption, which limits uptake of vitamin E.

“Low vitamin E levels plus high oxidative stress is a recipe for more inflammation, which can contribute to a range of negative health outcomes,” she said.

Traber and colleagues postulated that the oxidative distress caused by inflammation in cystic fibrosis increases vitamin E utilization, which could be positively influenced by supplemental vitamin C administration.

For the study, the researchers enrolled six adult patients with cystic fibrosis and moderately advanced respiratory tract disease. Patients consumed a standardized breakfast with 30% fat and a capsule containing 50 mg each hexadeuterium (d6)-alpha- and dideuterium (d2)-gamma-tocopheryl acetates immediately before and after receiving vitamin C (500 mg) twice daily for 3.5 weeks.

Researchers acquired blood samples frequently up to 72 hours and determined plasma tocopherol pharmacokinetics.

Results indicated that d6-alpha- and d2-gamma-tocopherols were comparably absorbed and reached similar maximal plasma concentrations at around 18 to 20 hours during both the baseline and vitamin C supplemented trials. Moreover, the rates of plasma d6-alpha-tocopherol decline were significantly slower during vitamin C supplementation (P < .05).

“Since vitamin E is hanging around longer, it might be able to get into tissues better, and better protect cell membranes from oxidative stress,” Traber posited in the release.

She further noted that, while the study suggested a high dosage of vitamin C may be beneficial in inflammatory conditions, it used an amount of the vitamin far in excess of what someone can easily obtain from the diet, likening 1,000 mg to 15 oranges or four or five medium bell peppers.

“It would seem to be clinically prudent for [cystic fibrosis] clinicians and nutritionists to recognize the importance of dietary and supplemental vitamin C levels and their possible impact on plasma alpha-tocopherol kinetics in their patients who are undernourished and/or experiencing severe exacerbations of their [cystic fibrosis respiratory tract] inflammatory disease,” the researchers wrote.

Reference:

• Cystic fibrosis patients can benefit from vitamin supplements, Oregon State research shows. https://today.oregonstate.edu/news/cystic-fibrosis-patients-can-benefit-vitamin-supplements-oregon-state-research-shows. Published Sept. 28, 2022. Accessed Oct. 5, 2022.