Do Low Vitamin B6 Levels Harm My Immune System?

Do Low Vitamin B6 Levels Harm My Immune System?

nutrients for immune function series

This blog is part 3 in my Nutrients for Immune Function Series on nutrition and its impact on immune function. If you missed the first two parts, I would make sure you check them out!

You can find part 1 here.

And part 2 here.

This content is based on information hosted by the National Cancer Institute (NCI), called Cancer Prevention Through Immunomodulation: Does Diet Play a Role? You can listen to the entire presentation here (click “View this webinar” under the Meeting Materials heading).

What is Vitamin B6?

Vitamin B6 is one of the water soluble vitamins. This means that it is found in the water component of the food we eat and not the fat or oil portion. It also means that excess B6 will be excreted in urine and not stored in our fat cells. B6 is actually seven different compounds, which have many roles in our body including metabolism and hemoglobin synthesis. If your vitamin B6 levels are too low, this can show itself as impaired glucose tolerance.

Do Low Levels of Vitamin B6 Impair My Immune System?

Vitamin B6 appears to play a role in immune function. For example, a significant portion of elderly people have low vitamin B6 levels. The elderly also have a less robust immune system. Low B6 levels have also been seen in cancer patients and low B6 levels are associated with an increased risk of breast cancer. These links are being investigated to see if there is causation or just simply correlation.

Do Low Levels of Vitamin B6 Promote Inflammation?

It was observed in the Framingham heart study that participants with lower levels of vitamin B6 had higher levels of inflammation. This is important because inflammation is associated with cancer and other chronic diseases. Specifically, the Framingham heart study found that those with B6 depletion have lower levels of lymphocytes and higher levels of neutrophils. The fact that neutrophils are high indicates the presence of inflammation. In addition, this observation of lower lymphocytes and higher neutrophils is important because researchers have discovered that the ratio of Lymphocyte:Neutrophil is an important predictor of survival from cancer. So, vitamin B6 deficiency affects both sides of this ratio in a negative way—you could call this a double-whammy!

Bottom Line

Vitamin B6 appears to be important in supporting a healthy immune system.

What Should I Do As A Cancer Survivor Who Wants To Thrive After Cancer?

Aim to meet your dietary requirement for vitamin B6. Recommended amounts are included in the table below. It is pretty easy to meet your requirement by eating a mixed diet as B6 is found in a variety of foods. Getting your B6 requirement from food is the preferred source—you will also get all of the other great nutrients that are found in the food item!

Certain populations are more at risk for deficiency including the elderly, alcoholics and people with type 1 diabetes, liver disease and rheumatoid arthritis. If for some reason you are not able to meet your requirement via diet, then you could consider a supplement. The supplement could be in the form of a multivitamin, B complex or stand-alone vitamin B6. It is important to respect the dosage and remember that more is not better—the upper limit is 100 mg per day. Also, it’s important to remember that taking a supplement is not an alternative to a healthy diet. The supplement should just be considered the safety net and not the long-term solution to a healthy diet.

Vitamin B6 Requirements

This table shows you some selected dietary sources of vitamin B6.

Vitamin B6 Food Sources


Achieving My Vitamin B6 Intake for the Day

Here is an example of how a person could achieve their daily vitamin B6 requirement by just selecting a few items from the list above. This isn’t a complete intake for the day, just a few selected items. As you can see, it’s pretty easy to meet or exceed the goal of 1.3 mg per day.

Selected Foods Eaten Throughout the Day

Food                                                               Vitamin B6


½ cup fortified breakfast cereal                  0.5   mg

1 banana                                                        0.4   mg


½ cup chick peas in salad at lunch              0.55 mg

Afternoon Snack

1 oz of nuts                                                    0.1   mg


3 oz of turkey at dinner                               0.4     mg

½ cup of squash at dinner                           0.2     mg

Total:                                                                         2.15   mg

Am I Getting Enough?

If you want to track your intake there are a couple of tools you can use. These require you to log your food intake and then they will provide the analysis of your intake. If you will embark on this, I suggest choosing 3 typical days to analyze.

Diet Analysis Tools

Super Tracker From the USDA

Eat Tracker from Dietitians of Canada

Stay tuned as I continue to discuss the interaction between diet and immune function. The next part in the Nutrients for Immune Function Series will be on the role of fish oil on immune function.


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