Editing Cystic fibrosis (section)

===Nutrient supplementation===
It is uncertain whether [[vitamin A]] or [[beta-carotene]] supplementation has any effect on eye and skin problems caused by vitamin A deficiency.<ref name="pmid30091146">{{cite journal | vauthors = de Vries JJ, Chang AB, Bonifant CM, Shevill E, Marchant JM | title = Vitamin A and beta (β)-carotene supplementation for cystic fibrosis | journal = The Cochrane Database of Systematic Reviews | volume = 8 | issue = 8 | pages = CD006751 | date = August 2018 | pmid = 30091146 | pmc = 6513379 | doi = 10.1002/14651858.CD006751.pub5 }}</ref>

There is no strong evidence that people with cystic fibrosis can prevent [[osteoporosis]] by increasing their intake of [[vitamin D]].<ref name="pmid24823922">{{cite journal | vauthors = Ferguson JH, Chang AB | title = Vitamin D supplementation for cystic fibrosis | journal = The Cochrane Database of Systematic Reviews | issue = 5 | pages = CD007298 | date = May 2014 | pmid = 24823922 | doi = 10.1002/14651858.CD007298.pub4 | pmc = 11254375 }}</ref>

For people with [[vitamin E]] deficiency and cystic fibrosis, there is evidence that vitamin E supplementation may improve vitamin E levels, although it is still uncertain what effect supplementation has on vitamin E-specific deficiency disorders or on lung function.<ref name="pmid32892350">{{cite journal | vauthors = Okebukola PO, Kansra S, Barrett J | title = Vitamin E supplementation in people with cystic fibrosis | journal = The Cochrane Database of Systematic Reviews | volume = 2020 | issue = 9 | pages = CD009422 | date = September 2020 | pmid = 32892350 | pmc = 8406985 | doi = 10.1002/14651858.CD009422.pub4 }}</ref>

Robust evidence regarding the effects of [[vitamin K]] supplementation in people with cystic fibrosis is lacking as of 2020.<ref name="pmid32497260">{{cite journal | vauthors = Jagannath VA, Thaker V, Chang AB, Price AI | title = Vitamin K supplementation for cystic fibrosis | journal = The Cochrane Database of Systematic Reviews | volume = 6 | issue = 6 | pages = CD008482 | date = June 2020 | pmid = 32497260 | pmc = 7272115 | doi = 10.1002/14651858.CD008482.pub6 | publisher = John Wiley & Sons, Ltd }}</ref>

Various studies have examined the effects of omega-3 fatty acid supplementation for people with cystic fibrosis but the evidence is uncertain whether it has any benefits or adverse effects.<ref name="pmid32275788">{{cite journal | vauthors = Watson H, Stackhouse C | title = Omega-3 fatty acid supplementation for cystic fibrosis | journal = The Cochrane Database of Systematic Reviews | volume = 4 | issue = 4 | pages = CD002201 | date = April 2020 | pmid = 32275788 | pmc = 7147930 | doi = 10.1002/14651858.CD002201.pub6 }}</ref>