Breast Cancer Treatment Associated with Lower Vitamin B Intake

Pharmacists may provide nutritional counseling regarding dietary adjustments or recommendations for over-the-counter supplements to assist patient with cancer.

Breast cancer accounts for 16% of all female cancers. Malnutrition may increase mortality and morbidity risk, and lengthens the cancer recovery process. Patients with cancer who undergo chemotherapy often experience adverse effects, such as early satiety, food aversions, loss of smell, loss of taste, and nausea, that prevent adequate food intake.

Previous studies have found that dietary intake of certain vitamins decreased in women undergoing chemotherapy treatment. One study observed that vitamins A, B3, and B6 intake were below the recommended value. Another study detected an inadequate dietary intake of vitamins B1,B2, B3, B6, and C.

The International Journal of Environmental Research and Public Health recently published a survey that assessed the impact of breast cancer treatment on dietary intake. Researchers surveyed women with noninvasive cancer undergoing chemotherapy for 3 consecutive days—before, during, and after treatment.

A computer program evaluated the nutritional value of food with regard to 13 vitamins: A, B1, B2, B3, B5, B6, B8, B9, B12, C, D, E, and K.

An analysis determined that intake of vitamins B2, B3, B5, and B8 decreased during and after chemotherapy compared to pre-treatment.

A separate analysis showed that during and after treatment, a deficit risk was possible with vitamins B5, B8, and B12.

Women who did not meet the Estimated Average Requirement for vitamin intake prior to treatment experienced even further reduction in vitamin intake post-treatment.

Is this decrease in vitamin intake important? Do patients need dietary supplementation?

The authors noted that a low dietary intake does not necessarily mean vitamin levels in the body are inadequate. Vitamin absorption and bioavailability varies from one person to another; therefore, blood samples are a better marker of malnutrition.

Prior to health care providers advising patients to take over-the-counter vitamin supplements, patients need a thorough evaluation. Lack of a given macronutrient can be detrimental, but so is having too much.

Sometimes nutritional counseling regarding dietary adjustments may be enough.

Justyna Sudyka is a 2021 PharmD candidate at the University of Connecticut in Storrs.


Morales-Suárez-Varela M, Ruiz Simon A, Blanch Tormo S, et al. Effect of breast cancer treatment on dietary vitamin intake levels. Int J Environ Res Public Health. 2021; 18(1):19.