Vitamin D in cancer and Covid-19
What is Vitamin D and does it have a role in fighting lung cancer and the Covid-19 virus?
Vitamin D is a fat-soluble vitamin that is naturally present in some foods (fish such as salmon, trout, or tuna) or available as a dietary supplement. Vitamin D can also be produced by our own body when ultraviolet rays from sunlight come in contact with the skin.
The vitamin must go through some modifications before it becomes active in the body. The first alteration occurs in the liver and the final change occurs in the kidneys.
Vitamin D helps with calcium absorption and boosts calcium and phosphate concentration levels for bone maintenance and muscle function. Many supplements also contain calcium and vitamin D together in one pill for this reason. Because of its importance in bone health, it is recommended that adults 50 years or older have 800 to 1000 IU* of vitamin D daily. In addition, the Endocrine Society and the American Geriatric Society recommend that adults 65 years or older also take 1000 IU* of vitamin D and calcium to reduce the risk of bone fractures.
Another role of vitamin D is to reduce inflammation, to affect cell growth, to modulate immune function, and to metabolize glucose. The receptor for Vitamin D has been found in many tissues. Research papers from as early as 2007 support its key role in modulating immune function. A search on Google Scholar (a Google search engine for scholarly research) for “vitamin D and immune system” yields more than ten pages of research in the last two years alone.
There has been some preliminary evidence that vitamin D may improve outcomes in cancer patients, however studying the direct effects of vitamin D on cancer has not yet yielded firm results. There are interesting correlations in breast cancer, colon cancer, skin cancer, prostate cancer, and more.
A global study in lung cancer was conducted in 2018. In this study, about 5313 lung cancer patients were followed and blood samples from 5 years prior to diagnosis were obtained. Vitamin D levels from the patients’ pre-diagnosis blood were analyzed. The odds ratio was calculated and there was no evidence that vitamin D can protect a patient from lung cancer compared to a control-matched group. (https://pubmed.ncbi.nlm.nih.gov/29617726/).
In a study done in 2018 in Japan, lung cancer patients with stage 1-3 were given vitamin D or a placebo and were followed for up to 9 years. There was a statistical advantage for longer survival when patients had higher levels of 25(OH)D {one of the active vitamin D alterations found in the blood}. (https://clincancerres.aacrjournals.org/content/24/17/4089.abstract).
The Covid-19 pandemic has again brought the role of vitamin D to the forefront. It is believed that vitamin D can help the immune system adjust to respiratory infections. However, an actual study of vitamin D’s role in Covid-19 has not been feasible because most hospitalized patients studied were already in the hyper-inflammatory phase of the Covid-19 infection. Vitamin D has been proposed to work in earlier phases of the infection.
Due to the combination of bone and muscular benefit and the potential to ward off respiratory illness, it is reasonable to add extra vitamin D to your diet, whether naturally or via a supplement. It is easy for primary care doctors to order a vitamin D level test to find out your current vitamin D levels. Bring up the topic and have a discussion with your healthcare provider. If you choose to take a Vitamin D supplement, please confirm with your doctor what is the suitable dosage for you.
*IU = International Unit. This is the unit for a fat-soluble vitamin to be biologically effective. This number is standardized across various forms of the same vitamin and is sold in various versions.
https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
https://www.nature.com/articles/nrc2196
https://www.thelancet.com/journals/landia/article/PIIS2213-8587(20)30268-0/fulltext
https://www.livestrong.com/article/408282-what-does-iu-mean-in-vitamins/
Author: Alice Chou