Why Deficiencies Develop — and How to Support Recovery

By, Dr. Sparks, ND, LAc

When someone has been sick for a long time after living or working in a water-damaged building, I often look at their nutritional status as one piece of a much larger clinical picture.

It is important to start with what we know from scientific research.

There is good evidence that certain mycotoxins—particularly food-borne mycotoxins such as aflatoxins—can negatively affect nutritional status. However, we have much less human evidence showing that typical indoor mold exposure directly causes specific vitamin or mineral deficiencies. In other words, we cannot currently say that exposure to household mold causes a particular vitamin or mineral deficiency in every person. There are not enough clinical trials in humans to establish that relationship.

Reasons for Depletion

What we do have are studies demonstrating several possible ways that mycotoxins could affect the digestive system, nutrient metabolism, and the intestinal environment. We also know that people who have been chronically ill may develop nutritional deficiencies for many other reasons.

Rather than assuming if mold caused a deficiency, I ask:

• What nutrients is this person getting from their diet?
• Are they properly digesting and absorbing those nutrients?
• Are they using certain nutrients at a higher rate in their biochemistry because of their health condition?
• Are medications, supplements, or other treatments interfering with absorption?
• Do their symptoms and laboratory results demonstrate a deficiency?

Giving someone nutrients can be extremely helpful when they are deficient. Vitamins, minerals, amino acids, fatty acids, and other nutrients provide the basic building blocks the body needs for normal cellular function, energy production, immune function, tissue repair, and many other processes. But simply giving supplements does not necessarily address the reason someone became deficient.

For example, imagine two people with low Vitamin D. One person may have low Vitamin D because they rarely consume Vitamin D containing foods and have limited sun exposure. Another person may have a gastrointestinal condition that interferes with the digestion or absorption of nutrients. Those two people may both have the same laboratory finding, but the reason for the deficiency, and therefore the most appropriate treatment approach, may be very different.

When someone has been living in a water-damaged environment, I also want to determine whether that environment could be contributing to the person’s overall illness.

Many people who come to my practice with chronic illness have significant gastrointestinal symptoms. They may have gas, bloating, constipation, diarrhea, food sensitivities, IBS-like symptoms, or other digestive complaints. Some have been diagnosed with conditions such as SIBO or dysbiosis. It is very reasonable to begin investigating the gastrointestinal tract when these symptoms are present. Digestion and absorption are essential for obtaining nutrients from food. If the intestinal tract is not functioning properly, a person may consume adequate amounts of nutrients but still have difficulty absorbing or utilizing them.

There is also scientific research that certain mycotoxins can affect intestinal cells and the intestinal barrier. Studies involving aflatoxin exposure, for example, have demonstrated changes to intestinal structures and tight junctions in animal models. These findings raise the possibility that some mycotoxins could interfere with normal intestinal function and nutrient absorption. However, animal research cannot automatically be translated into proof that indoor mold exposure causes nutrient malabsorption in humans.

Other research has investigated how mycotoxins may interact with the gut microbiome, intestinal immune system, and proteins that help maintain the intestinal barrier. These systems all play roles in digestion, absorption, metabolism, and transportation of nutrients. This gives us biologically plausible mechanisms to investigate, but it is still different from having clinical trials proving that indoor mold exposure causes specific nutritional deficiencies.

Vitamin B12 is one nutrient that I pay particular attention to when evaluating someone with chronic gastrointestinal problems. There have been clinical observation studies and hypotheses published regarding persistent B12 deficiency in people with chronic exposure to toxigenic molds. For example, Anyanwu et al described persistent B12 deficiency in patients with chronic mold exposure and proposed that mycotoxins might interfere with processes involved in B12 metabolism and utilization.

B12 deficiency has many well-established causes, including inadequate dietary intake, problems with stomach acid or intrinsic factor, gastrointestinal disorders, certain medications, and impaired absorption. Therefore, if someone with suspected mold illness has low B12, I don’t automatically assume mold is the cause. I investigate the entire picture.

Some research has examined the effect of Aflatoxin B1 on Vitamin D status. One study found that Aflatoxin B1 exposure could alter expression of the Vitamin D receptor, raising questions about whether certain mycotoxins could influence Vitamin D signaling and metabolism. Vitamin D levels can be affected by many factors, including dietary intake, sun exposure, body composition, liver and kidney function, gastrointestinal health, and certain medications. I prefer to measure Vitamin D rather than simply assume someone is deficient because it is a fat soluble vitamin that can be dangerous if it is too high.

Treatment Can Sometimes Causes Issues

Sometimes the nutritional deficiency can come from treatment. This is an area that I believe deserves attention. When someone discovers mold illness, they may begin making significant dietary changes or taking numerous supplements and treatments based on information they find online, from companies or from friends.  Sometimes these approaches are helpful and sometimes they can create additional problems.

For example, people following very restrictive diets may eliminate dairy, grains, fermented foods, histamine-containing foods, processed foods, sugar, or many other foods. They may have good reasons for avoiding some of these foods, particularly if certain foods consistently make them feel worse. But the more foods someone eliminates, the more important it becomes to make sure they are still getting adequate nutrition.

Some people use binders such as activated charcoal or clay as part of a mold-treatment strategy. Because these substances can bind minerals within the gastrointestinal tract, prolonged or poorly monitored use raises a reasonable concern about whether they could also interfere with the absorption of nutrients. Rather than assuming that a binder is either completely harmless or inherently harmful, I look at how it is being used, how long it is being used, what else the person is taking, and what their nutritional status looks like.

Cholestyramine is a bile-acid sequestrant. It works by binding bile acids in the gastrointestinal tract. Bile plays an important role in the digestion and absorption of dietary fats and fat-soluble vitamins, including vitamins A, D, E, and K. For this reason, long-term use of bile-acid sequestrants can be associated with reduced absorption of fat-soluble vitamins in some cases.

One situation I often encounter is a person who has been taking Vitamin D consistently, but whose blood level remains lower than expected. There can be several explanations, not following the dosing schedule, inadequate dose, limited sun exposure or an issue with digestion or absorption. I don’t believe that a low Vitamin D level automatically proves mold illness. But if someone has persistent gastrointestinal symptoms, multiple nutritional abnormalities, chronic illness, and a history of exposure to a water-damaged building, it is reasonable to investigate all these factors together.

Testing for Deficiencies

When someone comes to my office with gastrointestinal symptoms, chronic fatigue, suspected malabsorption, or a history of significant environmental exposure, I may evaluate nutritional status as part of a broader workup. Depending on the individual, testing may include things such as:

• Vitamin B12
• Folate
• Vitamin D
• Iron studies
• Magnesium
• Zinc
• Vitamin A
• Vitamin E
• Other nutrients based on symptoms, diet, medications, and medical history

I may also use more comprehensive testing, like a urinary Organic Acids Test, in selected patients when it is clinically appropriate. I don’t test every nutrient on every patient. Testing should be guided by the person’s history, symptoms, diet, medications, gastrointestinal function, and other laboratory findings.

In my clinical practice, I frequently see nutritional abnormalities in people who have chronic illness and who also report significant exposure to water-damaged environments.

Vitamin D is one of the abnormalities I commonly encounter, followed by nutrients such as B12, magnesium, zinc, iron, and sometimes vitamins A and E.

Foundational Steps

If we only treat the nutritional deficiency, we may miss the larger picture. Likewise, if we blame everything on mold without investigating other possible causes, we can miss important diagnoses. My approach is individualized, but I generally work in the following way:

1. Avoidance: No amount of supplementation can substitute for addressing an unhealthy environment. With mold, this means identifying and reducing exposure to water‑damaged buildings or contaminated environments, so the body is no longer constantly reacting to those triggers. It is the foundational step, because no treatment can outdo ongoing exposure. EC3 mold-cleaning products—like the EC3 Mold Spray and EC3 Laundry Additive—can help reduce mold load on surfaces and fabrics as part of a broader avoidance strategy.
2. Foundations and Protection: this will include nutrient supplementation, diet and lifestyle modifications
3. Drainage and Elimination: making sure pathways of elimination are functioning properly is key to success.
4. Binding and Elimination Strategies: These treatments should be individualized and monitored rather than approached as a one-size-fits-all protocol. I typically won’t use harsh binders on folks who have sluggish bowels. There are plenty of gentle binders out there that won’t constipate. Food‑based binders—such as Micro Balance Health Products’ Chitosan Bio‑Flav or biological binders, like IgG Gut Protect are options that can support binding without the same risk of constipation or aggressive mineral depletion. Of course, the choice depends on the patient and their individual needs.
5. Mold killing, biofilm breaking: during this phase the other phase all need to be working well so this phase will be more effective, and the patient will be less likely to have a Herxheimer reaction.
6. Repair and Rebuilding: This can include supporting nutritional status, gastrointestinal health, cellular function, hormonal rebalancing and other systems that may have been affected during a prolonged period of illness.
7. Reassessment: we typically will do follow up labs to see how someone is doing while also reassessing symptoms.

Currently, science does not allow us to say that indoor mold exposure definitively causes specific vitamin or mineral deficiencies in humans. What we do know is that chronic illness can make adequate nutrition more difficult, gastrointestinal problems can interfere with nutrient absorption, restrictive diets can reduce nutrient intake, and certain medications or treatments can affect nutrient absorption.

We also have experimental evidence showing that some mycotoxins can affect intestinal cells, the intestinal barrier, the microbiome, immune signaling, and pathways involved in nutrient metabolism. These findings provide reasonable biological hypotheses for further investigation.

References:

Anyanwu EC, Kanu I. Biochemical impedance on intracellular functions of vitamin B12 in chronic toxigenic mold exposures. Scientific World Journal. 2007 Oct 12;7:1649-57. doi: 10.1100/tsw.2007.113. PMID: 17982599; PMCID: PMC5900526.

Anyanwu EC, Morad M, Campbell AW. Metabolism of mycotoxins, intracellular functions of vitamin B12, and neurological manifestations in patients with chronic toxigenic mold exposures. A review. Scientific World Journal. 2004 Aug 26;4:736-45. doi: 10.1100/tsw.2004.133. PMID: 15349513; PMCID: PMC5956359.

Costanzo P, Santini A, Fattore L, Novellino E, Ritieni A. Toxicity of aflatoxin B1 towards the vitamin D receptor (VDR). Food Chem Toxicol. 2015 Feb;76:77-9. doi: 10.1016/j.fct.2014.11.025. Epub 2014 Dec 4. PMID: 25483621.

Damato A, Vianello F, Novelli E, Balzan S, Gianesella M, Giaretta E, Gabai G. Comprehensive Review on the Interactions of Clay Minerals With Animal Physiology and Production. Front Vet Sci. 2022 May 10;9:889612. doi: 10.3389/fvets.2022.889612. PMID: 35619608; PMCID: PMC9127995.

Du K, Wang C, Liu P, Li Y, Ma X. Effects of Dietary Mycotoxins on Gut Microbiome. Protein Pept Lett. 2017 May 10;24(5):397-405. doi: 10.2174/0929866524666170223095207. PMID: 28240164.

Mshanga N, Kassim N, Sonto S, Martin HD, Pirani M, Moore S, Auma CI, Kimanya M, Gong YY. A Cross-Sectional Association Between Serum Aflatoxin and Micronutrient Status Among Children Aged 6-24 Months in Rural Tanzania. Matern Child Nutr. 2025 Oct;21(4):e70068. doi: 10.1111/mcn.70068. Epub 2025 Jul 15. PMID: 40662698; PMCID: PMC12454167.

Mshanga N, Moore S, Kassim N, Martin HD, Auma CI, Gong YY. Association Between Aflatoxin Exposure and Hemoglobin, Zinc, and Vitamin A, C, and E Levels/Status: A Systematic Review. Nutrients. 2025 Feb 28;17(5):855. doi: 10.3390/nu17050855. PMID: 40077727; PMCID: PMC11902063.

About the Author:

Dr. Sparks is a Mold-Literate Naturopathic Physician and Acupuncturist. She is passionate about helping patients achieve their optimal state of health through one-on-one patient visits and lecturing nationwide. Dr. Sparks graduated with honors from Sonoran University of Health Sciences in Tempe, AZ. She has also earned a master’s degree in Classical Chinese Medicine from Daoist Traditions College in Asheville, NC. She truly believes in individualized care that encompasses mind, body and spirit. Dr. Sparks educates all patients on how to reclaim their health rather than simply cover up symptoms.

She uses functional lab analysis combined with time tested natural therapies like Clinical Nutrition, Supplementation, Biotherapeutic Drainage, Acupuncture, Chinese Herbal Therapy, Hydrotherapy, Western Botanical Medicine, Mind-Body Therapy and Homeopathy. She sees the entire picture, looks for the root cause and supports patients in walking the path to wellness that best suits them. Dr. Sparks has helped people with a vast array of issues including, mold illness, Lyme disease and con-infections, thyroid disorders, gastrointestinal disorders, respiratory issues, sleep, anxiety, depression, hormones, autoimmune disease, skin, EBV, chronic fatigue, men’s health, pediatric issues and Women’s Health from menstruation to menopause.

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