Taking vitamins or other supplements duringcancertreatment may have benefits, but there can also be risks.
When Do Oncologists Recommend Vitamins?
There are several reasons why your healthcare provider may recommend dietary supplements.
Verywell / Ellen Lindner
Talk to your healthcare provider about this possibility.
Some researchers have theorized that supplementation could help reducecancercachexia.
However, there is some evidence that omega-3 fatty acids may be helpful.
However, the research results are mixed on whether antioxidants are beneficial or harmful during chemotherapy.
This can be a problem in northern climates.
For this reason, many healthcare providers recommend a supplement of vitamin D3.
Who Should Take a Vitamin D Supplement?
Importance of Vitamin D
Vitamin D is not an antioxidant.
It functions more like a hormone than a vitamin in the body.
Vitamin D supplementationmay also help with cancer fatigue.
One small study showed cancer patients with higher vitamin D levels reported less fatigue and improved well-being.
Your healthcare provider will want to monitor your levels to see if they change if you begin a supplement.
The normal range of values may not be the ideal range for someone with cancer.
For example, the reference range for normal vitamin D levels is 3080.
Yet some studies suggest that a level of 50 is better than a level of 31.
Vitamin D supplementation is not for everyone.
There are potential side effects, including, kidney stones, if levels are too high.
But as with other vitamins, its important to talk to your healthcare provider before taking supplements.
There are several reasons why your oncologist may recommend that you avoid vitamin or mineral supplements.
This damage is called oxidative damage since the reaction involves oxygen.
Antioxidants may protect cancer cells from being damaged by chemotherapy and radiation therapy.
We dont want to protect cancer cells.
How vitamin C is given may also influence its effectiveness and risks.
In these studies, it was thought that vitamin C interfered withapoptosis(cell death) in cancer cells.
Inanimal studies, vitamin C appeared to reduce the anti-cancer activity of the targeted therapy Velcade (bortezomib).
Velcade is used for people with multiple myeloma and some types of lymphoma.
Some of the risks may be more theoretical.
The exception was one study that showed an increase in toxicity in those using a vitamin A supplement.
This review evaluated studies usingN-acetylcysteine, vitamin E, selenium, L-carnitine,Coenzyme Q10, and ellagic acid.
Of note is thatbiotinmay be present in many combination vitamin supplements.
Dietary Sources vs.
In general, the rule for getting vitamins and minerals during cancer treatment is food first.
Theories have been proposed to explain why supplements may increase cancer risk.
Sometimes taking a supplement for one concern may raise another.
An example is a study in which people with melanoma were treated with selenium.
There are also special cases that cant be addressed when studies look at the general population.
For instance:
The role of vitamins and antioxidants can also vary depending on particular treatments.
For example, vitamin C may reduce the effectiveness of radiation but may also reduce the toxicity.
Summary
Vitamin and mineral supplements during cancer treatment may have risks as well as benefits.
Benefits may include improving nutritional deficiencies, cancer fatigue, and cachexia.
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