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Four Vitamin Toxicities on a Gluten-Free Diet

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Four Vitamin Toxicities on a Gluten-Free Diet

vitamin overloadThis month I address a topic that is rarely covered in the media swirl surrounding the gluten-free diet, yet is vitally important. When symptoms are persistent while on a gluten-free diet, common culprits such as other food sensitivities or exposure to gluten are evaluated, as I addressed in a previous column on ongoing symptoms.  While these factors are often the cause and are important to consider, they aren’t the only reasons for symptoms to persist. At times, ongoing symptoms are a result of the treatment itself.

Patients are becoming more aware that they are at risk for vitamin and nutrient deficiencies on a gluten-free diet. Common deficiencies include vitamin D, iron, B vitamins, calcium, zinc, copper, and vitamins A, E and K. As supplements are easily available over the counter, patients on a gluten-free diet are taking them to prevent deficiencies or address persistent symptoms. Supplements can be beneficial, but they need to be used with caution.

A patient recently came to my office for chronic digestive symptoms. She was on a gluten-free diet for non-celiac gluten sensitivity. During her initial visit, she mentioned painful burning and numbness she had been experiencing in her feet for about a year. As many people do, she had started herself on nutritional supplements to ensure she was getting adequate vitamins and minerals.  She knew the gluten-free diet could be deficient in many nutrients so she wanted to safeguard against any potential problems. What she didn’t realize, however, was that supplements can be toxic, even to those at risk of deficiency.

When her vitamin B6 level came back “too high to count,” we addressed the safe use of vitamins and supplements, an important topic for anyone taking nutritional supplements.

Since her recent visit, I have seen many other patients with vitamin toxicities due to supplements they were taking before our initial visit, suggesting this issue may be more common than is realized. It is difficult to say how common it is as there is little to no medical data on vitamin toxicity while on a gluten-free diet. The cases I have seen all occurred in people taking supplements. Below are four examples of vitamin toxicities I have seen the most in my practice, although the potential for toxicity exists with other vitamins taken in supplementation.

1. Vitamin B6

Taking high doses of vitamin B6 for prolonged periods can lead to permanent nerve damage.

B6 Neuropathy imageVitamin B6 serves as a co-factor (helper) for many metabolic functions in the body. It is vital in maintaining health, but when taken at high doses for prolonged periods of time, it can cause nerve destruction. If high blood levels are not addressed, the damage can be irreversible. Common symptoms of vitamin B6 toxicity include painful numbness and tingling of the hands and feet, ataxia (loss of coordination in body movement), painful skin lesions, nausea, heartburn and photosensitivity.

Recommended doses vary, but suggested doses for adults range from 1-2mg per day. Many supplements contain much higher quantities. Recommended amounts for a safe upper limit of normal range from 50mg-100 mg per day. If blood levels are found to be high, all supplements containing vitamin B6 should be discontinued until levels return to normal. Good food sources of vitamin B6 are whole grains, chickpeas, starchy vegetables such as potatoes and organ meats. There are no reported cases of B6 toxicity from food sources.

2. Iron

Iron deficiency is common whether or not a person is on a gluten-free diet, but taking iron without appropriate monitoring can be dangerous.

joint pain image- iron overloadIron is essential for carrying oxygen in the blood. It is also needed for many enzymes and proteins to function. Although it is an essential nutrient, the potential for iron toxicity is high because very little of it is excreted from the body. Symptoms of iron overload include joint pain, fatigue, weight loss, nausea and stomach pain.

A very common genetic condition called hemochromatosis occurs in 1% of the population. Most people with this condition do not know they have it. People with hemochromatosis are very efficient at absorbing iron.  When iron accumulates in the body, it deposits in body tissues and in organs like the liver.  I have seen several cases of hemochromatosis in the past few months, as it is not rare. If someone with this very common condition takes iron supplements, they can become iron toxic rather quickly.

If iron levels are elevated, typically stopping all iron is all that is needed. If the person has hemochromatosis, frequent blood draws ( a process known as therapeutic phlebotomy) may be needed to get iron levels back to the normal range.

The recommended daily intake for adults is based on age and ranges from 8-18mg per day. Tolerated upper limits are 45mg per day. Supplementation beyond the daily recommended amount should be under medical supervision and should not be undertaken without first evaluating baseline level. Food sources of iron include liver, beef, chicken, fortified cereals, beans, lentils, spinach and molasses.

3. Vitamin A

Vitamin A is necessary for normal vision, organ and immune function as well as reproduction, but toxicity can cause serious symptoms.

There are two forms of vitamin A:

Dizzy-headache Vit A– Preformed (animal sources and many supplements) In supplements the preformed vitamin A is typically called retinyl acetate and retinyl palmitate.

– Provitamins (plant sources and some supplements) In supplements this form of vitamin A is called beta carotene. Provitamins do not appear to be toxic, but can turn the skin orange if ingested in very high amounts.

High intake of the preformed types of Vitamin A are associated with toxicity, and can cause nausea, dizziness, elevated intracranial pressure (pressure around the brain), headaches, coma and death. High vitamin A levels during pregnancy are associated with birth defects. The recommended daily intake of vitamin A is 2300 IU for women and 3000 IU for men. The recommended daily allowances differ during pregnancy and for children based on age. The daily upper safe limits for Vitamin A are 2000 IU for infants, 3000-5000 IU for children (depending on age) and 10,000 IU per day for adults.

If levels are elevated, treatment typically consists of stopping all supplements. If someone has neurologic symptoms, additional treatments or medications may be required. Food sources of preformed vitamin A are liver and fish oil, milk, and eggs. Good plant sources of vitamin A are sweet potato, spinach, carrots and pumpkin.

4. Vitamin D

Vitamin D has become a panacea, but high doses can work to our detriment.

Vitamin DVitamin D is important for numerous functions in our body including healthy bone formation, calcium regulation, neuromuscular and immune function. It is also important in minimizing inflammation. It is present in very few foods unless they are fortified, but is produced by our bodies when we are exposed to sunlight. Due to lack of dietary sources and minimal exposure to sunlight for many people, toxicity is rare unless supplementation is taken.

Symptoms of toxicity are vague and include poor appetite, weight loss, irregular heart rhythms and increased urination. Recommended daily intake ranges from 400-600 IU per day, depending on age, but there has been a movement to shift that recommendation closer to 1000-2000 IU per day based on more recent findings. Daily upper tolerable limits range from 1000 IU – 4000 IU per day depending on age. Clinically, many patients require higher doses to maintain adequate serum levels so monitoring is necessary.

If levels are unsafely elevated, stopping supplementation is all that is required. Food sources of vitamin D include fortified products such as milk, cereals and orange juice. Small amounts of vitamin D are found in beef liver and egg yolks.

Back to my patient  We stopped all her vitamins that contained B6 and her levels came down. Her numbness and tingling are resolving, and with time have a good chance of disappearing completely. I hope her story and this information makes you more aware of the caution to be taken with supplements. They can be very helpful in improving health, but please use them with care and under the supervision of a health care practitioner.


Past columns by Dr. Burkhart:

April/May 2016: Reasons People Follow a Gluten Free Diet: 7 Types of Gluten Free Dieters 

March 2016: Ten Positive Aspects of a Celiac Disease Diagnosis

February 2016: Gluten Causes Keratosis Pilaris (a.k.a. “Chicken Skin”): Fact or Myth?

January 2016: Fingernail Changes in IBS,Gluten Disorders and Celiac Disease “A window to health”

December 2015: 20 Gluten-Free Gift Ideas: From Budget to Luxury, Sentimental to Practical & More

November 2015: Cold Sores, Canker Sores and Gluten

October 2015: Celiac Disease and Gluten Sensitivity Research: Snippets from ICDS 2015 (Part 2)

September 2015: Celiac and Gluten Sensitivity Research: Ten Snippets from ICDS 2015

July/August 2015: A New Home Test To Monitor Gluten Exposure

June 2015: Six Reasons to Test for Celiac Disease Before Starting a Gluten-Free Diet

May 2015: POTS, Celiac Disease and Gluten: An Undiscovered Connection?

February/March/April 2015: Arsenic in the Gluten-Free Diet: Facts and Tips

December 2014/ January 2015: The Microbiome and Celiac Disease: A Bacterial Connection

November 2014: Celiac disease and gluten sensitivity: The doctor-patient disconnect

October 2014: Should You Trust Gluten-Free Labels?

September 2014: Triggers for celiac disease: One possible answer

July/August 2014: Ten Tips for a Healthier Gluten-Free Diet

June 2014: Back Pain and Gluten

May 2014: Self-Diagnosis of Gluten Sensitivity: Four Alarming Trends

April 2014: Update on Restaurants and Gluten-Free Dining

March 2014: Histamine Intolerance: Could it be causing your symptoms?

February 2014: Celiac Disease and Non-Celiac Gluten Sensitivity (Reprinted with permission from Sonoma Medicine)

January 2014: Four Vitamin Toxicities on a Gluten-Free Diet

December 2013: Move Over Gluten-Free, Low FODMAP is Next

November 2013: SIBO, Gluten and IBS: What Is The Connection?

October 2013: Pesticides, Wheat and Gluten Sensitivity: What is the Connection?

September 2013: Is gluten really the culprit in gluten sensitivity?

August 2013: Clarifying the Gluten-Free Labeling Rule

June/July 2013: No such thing as Mild Celiac Disease

May 2013: Magnesium Deficiency

April 2013: Six Reasons to test for celiac disease before starting a gluten-free diet

March 2013: Why am I having migraines?

February 2013: What is fructose malabsorption?

January 2013: Educating doctors about celiac disease

December 2012: Are supplements to digest gluten safe and useful?

November 2012: Top 5 reasons for persistent symptoms after Going Gluten Free

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“I have been a patient of Dr. Amy Burkhart for several years. I suffer from Crohn’s disease and was having difficulty in my daily life. After visiting many doctors, all of whom were unable to help me, Dr. Burkhart took the time and patience to create a plan which brought me back to health. I still follow her plan to this day and have been living a normal healthy life. Dr. Burkhart listened to my symptoms along with listening to me, she took her time in preparing a plan which led me to the road for recovery. I cannot thank Dr. Burkhart enough, and I would recommend her to anyone.”

8 months ago

Stone Brewing company Stone Brewing - Napa opened recently in Napa in an historic building adjacent to the river. A great venue to enjoy life! The gluten free menu options are coming (per the manager ) but please visit and inquire about GF options. The more people who show interest and discuss cross contamination the more likely they are to get it right! Wine is available. Maybe they will even consider a GF beer! . ... See MoreSee Less