Safe Supplement Practices for Chronic Illness Management
When managing a chronic illness, supplements often play a crucial role in supporting health and alleviating symptoms. Research shows that up to 87% of those with ME/CFS take supplements (1), and 60–75% of fibromyalgia patients rely on supplementation for symptom relief (2). This is significantly higher than the 30–50% supplement usage in the general population (3).
The high rate of supplement use among individuals with ME/CFS, fibromyalgia, and long-haul COVID is likely due to the lack of effective medications and inadequate healthcare management. However, not all supplements are created equal. Poor-quality products can fail to provide the expected benefits and may introduce harmful contaminants or imbalanced dosages that can negatively impact health or worsen symptoms.
For individuals with chronic illnesses, who often have increased sensitivities and metabolic vulnerabilities, supplement quality isn’t just a matter of preference—it’s essential for safety and efficacy. This article will explore common supplement toxicities, nutrient interactions, and how to choose pharmaceutical-grade supplements to support your health safely.
What Causes Supplement Toxicity?
Toxicity can occur due to several factors, including:
Excessive Dosages: Taking more than the body can process effectively.
Poor-Quality Ingredients: Many supplements contain contaminants, fillers, or inconsistent dosages. Heavy metals are often found in low-quality products. Checking Consumer Reports or third-party testing certifications on the company website ensures safety.
Interactions with Medications: Certain supplements can interfere with prescription medications, amplifying or reducing their effects.
Vitamin B6 (Pyridoxine) Toxicity
Many supplements commonly used by post-viral patients contain this vitamin. Combination products for energy, brain health, or immune support commonly contain B6, making it quite easy to overdo this vitamin. Excessive B6 intake can lead to peripheral neuropathy, causing numbness and tingling in the hands and feet. Check Your Labels!
Also remember that up to 65% of gut bacteria synthesize B6 naturally, making true deficiency rare while toxicity is a more common concern.
RDA for Vitamin B6:
Men: 1.7 mg/day
Women: 1.5mg/day
Tolerable Upper Limit (UL): 12 mg/day
Vitamin A Toxicity
Vitamin A is vital for vision, immune health, and skin integrity, but it’s also one of the most toxic vitamins when taken in excessive amounts. Excess vitamin A can lead to headaches, nausea, dizziness, liver damage, and even osteoporosis. Pregnant individuals should be especially cautious, as high doses can cause birth defects. If taking a multivitamin, be careful to add any other product that may contain vitamin A.
Avoid excess intake from multiple sources (e.g., multivitamins, cod liver oil, liver-based foods).
RDA for Vitamin A:
Men: 900 mcg/day (3,000 IU)
Women: 700 mcg/day (2,333 IU)
Tolerable Upper Limit (UL): 3,000 mcg/day (10,000 IU)
Common Supplements That May Damage the Liver
The liver plays a critical role in detoxifying the body, processing medications, and metabolizing nutrients. However, certain supplements, especially when taken in excessive doses or of poor quality, can strain the liver and lead to toxicity or damage. For individuals managing chronic illnesses, the liver is often already under stress, making it even more essential to avoid supplements that could exacerbate the problem.
1.Green Tea Extract (EGCG)
Excess EGCG (epigallocatechin gallate) can lead to liver toxicity. If your urine turns dark brown, it may indicate liver strain. The product should be discontinued if this occurs.
Safe Dosage: 300–400 mg/day
Toxicity Risk: Exceeding 800 mg/day has been linked to liver damage.
2. Ashwagandha
Ashwagandha is a popular adaptogenic herb used for stress relief, adrenal support, and cognitive enhancement. However, recent reports have raised concerns about potential liver toxicity. Some case studies have reported liver enzyme elevation and even drug-induced liver injury (DILI) after prolonged high-dose ashwagandha use.
Safe Dosage: (300–600 mg/day)
3. Kava
Used for anxiety and sleep, kava is associated with liver failure, especially when combined with alcohol or other medications.
4. Turmeric (Curcumin)
While turmeric is popular for inflammation and pain relief in those with ME/CFS and fibromyalgia, excessive doses can impair liver function. Additionally, some turmeric supplements contain lead-based synthetic dyes (lead chromate), further increasing health risks (4).
Safe Dosage: 500–1000 mg/day
Signs of Toxicity: Fatigue, jaundice, nausea
Supplements That Act as Blood Thinners
Some supplements have natural blood-thinning properties, which can be beneficial in certain contexts but pose significant risks if not used carefully. Blood-thinning supplements reduce the blood's ability to clot, which can help prevent issues like stroke or heart attack. However, when taken in excessive amounts or combined with medications that also thin the blood, these supplements can increase the risk of bleeding. Some common examples include:
Curcumin (turmeric)
Fish Oil (Omega-3s)
Garlic Extract
Ginkgo Biloba
Safe Use: Always consult your doctor before combining these supplements with blood-thinning medications or if surgery is planned.
Excessive Dosages Can Disrupt Nutrient Balance
More isn’t always better. Excessive dosages of one nutrient can interfere with the absorption, metabolism, or function of others, creating harmful imbalances. Below are some common products that, when taken alone, may throw off the balance of another. For this reason, it is important to check your labels or opt for a multivitamin/multimineral product instead of taking individual nutrients.
Vitamin D and Calcium
Vitamin D is essential for calcium absorption and plays a critical role in maintaining healthy bones. However, taking excessive amounts of vitamin D can lead to an overload of calcium in the bloodstream, a condition called hypercalcemia. This can cause symptoms like nausea, fatigue, kidney stones, and even damage to the kidneys and heart. Over time, this can result in inefficient absorption of calcium and potential calcification of arteries (5).
Excess vitamin D can cause calcium buildup in the bloodstream (hypercalcemia), leading to kidney stones or arterial calcification (5).
Recommended Ratio: 40:1 (Calcium:Vitamin D)
Example Dosages:
Calcium: 1000–1200 mg/day
Vitamin D: 1000 IU/day
Magnesium and Zinc
Magnesium and zinc compete for absorption in the body. Since magnesium is crucial for muscle function, nerve signaling, and cardiovascular health, an imbalance can contribute to symptoms like muscle cramps, fatigue, and irregular heart rhythms. Conversely, excessive magnesium intake can impair zinc absorption, which is critical for immune function and wound healing. Maintaining a proper ratio of these minerals is essential to avoid unintended deficiencies or toxicities. Studies also show that a high magnesium-to-zinc ratio can promote calcification of arteries (6).
High zinc intake inhibits magnesium absorption, potentially leading to muscle cramps and irregular heart rhythms (6).
Recommended Ratio: 10:1 (Magnesium:Zinc)
Example Dosages:
Magnesium: 300–400 mg/day
Zinc: 30–40 mg/day
Zinc and Copper
Zinc and copper share a transporter protein in the gut, meaning they rely on the same pathway for absorption. This means that excessive zinc can indirectly deplete copper levels, even if dietary copper intake remains adequate. A copper deficiency can cause a range of health issues, including iron deficiency anemia, impaired production of white blood cells, nerve damage, and joint pain.
Oxidative stress plays a major role in raising the levels of copper and zinc, especially important for those with post-viral conditions. With oxidative stress, there is an overall decrease in plasma zinc and an increase in plasma copper (7). The best idea is to check the blood levels of these minerals before starting a supplement. There are multivitamins/multiminerals available that are copper-free.
Excessive zinc depletes copper, leading to anemia and immune dysfunction.
Recommended Ratio: 8:1 (Zinc:Copper)
Example Dosages:
Zinc: 30 mg/day
Copper: 3 mg/day
Tips for Safe Supplement Use
By understanding the risks associated with excessive dosages, you can make informed decisions about which supplements to include in your routine. As always, opting for pharmaceutical-grade products ensures precise dosing and reduces the likelihood of harmful side effects. Pharmaceutical-grade products mean that they are only sold through healthcare providers and they are subject to third-party testing and/or voluntary FDA inspection. These products do tend to be more expensive, but you are paying for better quality and quality standards. It’s worth it.
Stick to recommended dosages. Avoid “mega” dosing unless under strict medical supervision.
Avoid combining supplements with similar effects (e.g., multiple blood thinning products).
Avoid taking individual minerals or vitamins to avoid throwing off key ratios.
Routinely check the blood for liver damage (ALT, AST) or mineral balance issues
Consult healthcare providers before starting new supplements if you take multiple medications or have serious medical conditions like kidney or liver disease.
Final Thoughts
With chronic illnesses like ME/CFS, fibromyalgia, and long-haul COVID, supplements are an integral part of symptom management. However, quality matters—choosing pharmaceutical-grade supplements reduces risks and ensures you get the benefits you need. I offer such products to readers through my FullScript store. Also remember that less is more. Supplement smarter for your unique health challenges and avoid excess.
References
1. Weigel B, Eaton-Fitch N, Passmore R, Cabanas H, Staines D, Marshall-Gradisnik S. A preliminary investigation of nutritional intake and supplement use in Australians with myalgic encephalomyelitis/chronic fatigue syndrome and the implications on health-related quality of life. Food Nutr Res. 2021;65:10.29219/fnr.v65.5730. Published 2021 Jun 7. doi:10.29219/fnr.v65.5730
2. Arranz LI, Canela MÁ, Rafecas M. Dietary aspects in fibromyalgia patients: results of a survey on food awareness, allergies, and nutritional supplementation. Rheumatol Int. 2012;32(9):2615-2621. doi:10.1007/s00296-011-2010-z
3. National Center for Health Statistics. Dietary Supplement Use Among U.S. Adults Aged 20 and Over. Centers for Disease Control and Prevention. Published April 2021. Accessed January 11, 2025. https://www.cdc.gov/nchs/products/databriefs/db399.htm
4. Halegoua-DeMarzio D, Navarro V, Ahmad J, et al. Liver Injury Associated with Turmeric-A Growing Problem: Ten Cases from the Drug-Induced Liver Injury Network [DILIN]. Am J Med. 2023;136(2):200-206. doi:10.1016/j.amjmed.2022.09.026
5. Khazai N, Judd SE, Tangpricha V. Calcium and vitamin D: skeletal and extraskeletal health. Curr Rheumatol Rep. 2008;10(2):110-117. doi:10.1007/s11926-008-0020-y
6. Al-Qaridhi A, Ghosh S, Luo D, Huang H. Magnesium and Zinc Intake Ratio Mediates the Increase of Coronary Artery Calcification through Upregulating Interleukin 6. Libyan J Med. 2022;17(1):2028997. doi:10.1080/19932820.2022.2028997
7. Malavolta M, Piacenza F, Basso A, Giacconi R, Costarelli L, Mocchegiani E. Serum copper to zinc ratio: Relationship with aging and health status. Mech Ageing Dev. 2015;151:93-100. doi:10.1016/j.mad.2015.01.004
