Vitamin toxicity is a dangerous disorder which can interfere with important bodily functions. Excessive vitamin and supplement intake can cause serious health problems, including neurological symptoms, endocrine syndromes, and more. Many health conscious people take herbal supplements and extra vitamins – if you are one of them, beware! Here are three reasons it happened to me, and five tips to prevent it from happening to you.
The phrase “too much of a good thing” is oft heard from parents, trying to prevent their children from over indulging or over extending themselves. According to the Oxford Dictionary of Proverbs, the idiom’s modern form first appears in Shakespeare’s As You Like It, but many similar sentiments were expressed hundreds of years before William Shakespeare was born . While this saying may be especially true when referring to chocolate, it also applies to seemingly benign vitamins and supplements.
Vitamin toxicity typically manifests after a person has taken vitamins and supplements for an extended period of time . Many people take vitamins, multivitamins, and supplements daily. Combining supplements with high potency vitamins can easily lead to vitamin overdose. Under the watchful eye of a doctor, some vitamins can be taken at higher doses than the recommended daily value. As long as the daily dose of the vitamin remains under the tolerable upper intake level, the risk of adverse effects is low . Some vitamins have no upper limits, but many fat-soluable vitamins have relatively low limits. These include Vitamins A, D, E, Niacin, and Chloline. Vitamin B6 is accumulated in the muslces and liver, although it is water soluble. .
Vitamin Toxicity happened to me. Here’s How:
Multivitamins are High Potency
The multivitamin I was taking had 153% of the recommended daily value of Vitamin B6 . This would be an appropriate level of Vitamin B6 you did not obtain it from any other source, including your diet, or you required it for some therapeutic effect. Besides my daily multivitamin, I would occasionally take a mixed Vitamin B gummy to fight fatigue, as recommended by a doctor. This had 200% of Vitamin B6 . These are standard, plain, multivitamin complexes. These are likely to be very similar to what is in your cabinet or drawer. Despite Vitamin B6 being water soluble, it still accumulates in the body with a half-life of 25 days .
Additionally, I took more supplements which contained Vitamin B6. Hemp seed oil contains high levels of Omega 3 ALA, which is beneficial for many disorders and to buffer against aging. Hemp seed oil is also a good source of Vitamin B6 . At that time, I took a small capsule of it daily. Additionally, I used the herbal remedy Tart Cherry in a concentrated form. Tart cherries are great antioxidants and are considered a superfood – and a good source of Vitamin B6 . The issues really began when I purchased an extremely fresh bottle.
It is well known that many vitamins are degraded by heat, light, humidity, and by being outside a protect environment. That is not well known is that vitamin and supplements manufacturers may increase potency above stated levels to compensate . That fresh bottle of tart cherry extract could have included additional antioxidants to preserve it during a six month sit on a store shelf. It could have been the standard, and I was used to a more degraded product. It was much fresher with a brighter, more saturated pink color and fruit smell. But it definitely did not match the stated potency – because there was no stated potency!
Manufacturers Are Not Required to Report All Vitamins 
Per the FDA’s FAQ for supplement facts:
Must I declare vitamins and minerals (other than vitamin A, vitamin C, calcium, and iron) listed in 21 CFR 101. 9(c)(8)(iv) and (c)(9)?https://www.fda.gov/food/dietary-supplements-guidance-documents-regulatory-information/dietary-supplement-labeling-guide-chapter-iv-nutrition-labeling#4-2
No. You are only required to declare them when they are added to the product for purposes of supplementation, or if you make a claim about them.
See 21 CFR 101.36(b)(2)(i)
Tart Cherry, Hemp Seed Oil, and many other supplements contain natural levels of Vitamin B6 and many others not listed above. How much Vitamin B12 is in your daily protein powder? Who knows! How much Vitamin K is in your turmeric capsule? The manufacturer won’t say! The reishi mushroom is high in potassium, but you won’t find out how much it has from the label. This can make it extremely difficult to keep track of your daily vitamin intake.
Lastly, I Ignored the Symptoms
My toes had started to go numb. I had an increased amount of muscle spasms. I started suffering from an unnerving amount of muscle twitches and my fatigue was worsened. Unfortunately for me, many of these symptoms mimic a flare up of autoimmune myelitis – which I already have and manage. I was not alarmed enough to make a doctor’s appointment for a few months, so the levels of B6 continued to grow and build up in my body.
I waited until my next scheduled MRI and expected the worst news, but everything looked normal. It sure didn’t feel normal. Blood tests followed, and revealed extremely high Vitamin B6. My medications, vitamins, and supplements were carefully reviewed. I have a known Vitamin B12 deficiency, which was taken into account. Vitamin B6 is tricky, toxicity and deficiency have the same symptoms. High Vitamin B6 levels can mask a Vitamin B12 issue. I brought a big grocery bag full of my pills to the doctor and we poured over them. None of them stated they had extra B6, so supplements had to be eliminated one by one.
The next part was the hardest – stop taking everything non-essential, and wait. Slowly add beneficial supplements back to my rotation. Research, research, research.
What Can You Do to Prevent Vitamin Toxicity?
What can be done, besides avoiding taking any extra vitamins? That isn’t always feasible, especially those of us who are prescribed daily vitamins by our doctors. For example, many people need to take a Vitamin B12 supplement. Some people cannot absorb enough Vitamin B12 because of aging, stomach disorders, autoimmune disorders, and happening to have a thin stomach lining . There are many other vitamins and many other reasons that doctors many prescribe supplements. I have been personally been prescribed a few. Therefore, the “easy answer” of shunning all vitamins will not do.
Here are 5 Tips to Prevent Vitamin Toxicity from Happening to You:
1. Tell Your Doctor About ALL of Your Vitamins & Supplements
Every single one! Even if you only take echinacea when you have the sniffles or use topical CBD when you hurt your elbow, tell your doctor. It is better to review a long list of vitamins, herbs, and supplements than it is to become sick from missed interactions. Many doctors have a patient data repository which saves this information for them to review at any time, and makes it easy to go over your supplements with your doctor.
2. Complete All of Your Regular Medical Tests, Appointments, and Blood Work
Don’t miss blood work! And if there is any issues, do not be afraid to ask for additional tests, within reason. Many doctors and health insurance plans have no issues doing regular blood work to verify vitamin levels and general health statistics. It is easy, only takes a few minutes (aside from the wait), and can help detect major problems before they can manifest symptoms.
3. Take Half Of Your Multivitamin
If you are otherwise healthy and eat adequate fruits and vegetables, multivitamins may not provide you with any benefits . Many people with medical issues, specifically diabetics , gain benefit from daily vitamin supplementation of Vitamin D and Vitamin B12 (myself included!). But most multivitamins and multiminerals provide too high a potency for your body to absorb. Speak to your doctor about if they are necessary – and if they are, only take half! If your urine is especially bright or dark, you are flushing much of your vitamins down the toilet. If you eat fruits and vegetables, only half of a daily vitamin is necessary.
The easy way to split your multivitamin dose in half is to find a vitamin which requires two capsules or gummies per dose, and only take one. I take a multivitamin which calls for two gummies per dose. I only take one. Gummies are also easier on my stomach, but that is my own personal microbiome and biochemistry.
4. Skip Supplements on the Weekend
Unless you are specifically deficient in a vitamin and prescribed by doctors to take it every day, skip it every weekend. Give your stomach and your fatty vitamin stores a break. Your supplements will be there for you on Monday, and a few less pills per year will help your pocket book. This will allow your body to use up any water soluble vitamins and lessen the impact of fat soluble accumulation.
In addition to this, I will often skip taking my multivitamin completely one day in the middle of the week. I sometimes skip others because I simply do not feel like swallowing large pills first thing in the morning. I figure that it cannot hurt, as long as my blood work remains normal.
5. Research Your Supplements and Find Out What’s In Them
The best place to start is to simply search “[supplement name] vitamin toxicity”.
This should be done for all of the vitamins you take. For example, let’s say you want to take Ginkgo Biloba. I would search for “ginkgo vitamin toxicity”. The first results mention vitamin B6, which is scary! But upon closer review, it appears that untreated seeds cause this type of toxicity. Reputable supplements will not have this issue. Next, I would find an article like this to learn more about how this herb may interact with any medications I take.
If you take any medicines or are diagnosed with any illnesses, it is very important to check for drug interactions and contraindications. Sometimes doctors leave it to the pharmacist to catch drug interactions, and sometimes the pharmacist will assume the doctor knows and is monitoring them. Every time I am prescribed a new medication or wish to take a new supplement, I do my own independent research. Unless your doctor acknowledges a drug interaction and monitors for it, contact them immediately if one is found. This extends to herbs and vitamins.
There are many reputable secondary source websites which contain information about herbal supplements. Many of these have reports about medicines which interact with herbs as well as medical issues which may be contraindicated. Unfortunately, many plants may lack clinical studies. The medicine you take may have not been studied with the remedy you wish to try. That is why it is important to start with low doses!
After I complete my general search, I look on websites like these to find more data:
Web MD Vitamins & Supplements
If you can’t find what you are looking for via normal web search, use these websites:
These last websites are where I find most of my open-access primary research. Here you can see charts with detailed chemical breakdowns of plants. This may be pretty dense reading material for most, but useful if you need to share the research with your doctor.
Remember, you are your best advocate! Question where the information you read comes from. The information in this blog post came from the sources listed below.
Do you like the information I have accumulated, and would like to support this site? Please consider donating:
- “You can have TOO much of a good thing.” Oxford Dictionary of Proverbs. Ed. Speake, Jennifer. : Oxford University Press, , 2015. Oxford Reference. Date Accessed 29 Apr. 2021 <https://www.oxfordreference.com/view/10.1093/acref/9780198734901.001.0001/acref-9780198734901-e-2293>. (Note – You can find more information using the site’s search function).
- Hemminger A, Wills BK. Vitamin B6 Toxicity. [Updated 2020 Nov 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554500/
- Center for Food Safety and Applied Nutrition. “Dietary Supplement Labeling Guide: Chapter IV.” U.S. Food and Drug Administration, United States of America, Apr. 2005, <https://www.fda.gov/food/dietary-supplements-guidance-documents-regulatory-information/dietary-supplement-labeling-guide-chapter-iv-nutrition-labeling#4-2>.
- Office of Dietary Supplements. “Nutrient Recommendations : Dietary Reference Intakes (DRI).” National Institute of Health, U.S. Department of Health and Human Services, <https://ods.od.nih.gov/HealthInformation/Dietary_Reference_Intakes.aspx>.
- Alive! Gummy Multivitamin <https://www.naturesway.com/products/alive-womens-gummy-multivitamin> and Alive! B-Complex Gummy <https://www.naturesway.com/products/alive-b-complex-gummies>
- “Vitamin B12: What to Know.” WebMD. July 2021 <https://www.webmd.com/diet/vitamin-b12-deficiency-symptoms-causes>
- Marengo, Katherine. “9 Benefits of Hemp Seeds: Nutrition, Health, and Use.” Medical News Today, MediLexicon International, 11 Sept. 2018, <https://www.medicalnewstoday.com/articles/323037>
- Parsaei, Parvin et al. “Determination of some B Vitamins in Sour Cherry Juice Using Dispersive Liquid-liquid Microextraction Followed by High-performance Liquid Chromatography.” Iranian journal of pharmaceutical research : IJPR vol. 13,4 (2014): 1437-45. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4232812/>
- “Degradation of Vitamins, Probiotics and Other Active Ingredients Caused by Exposure to Heat, Water and Sunlight.” Nutraceutical Business Review, 7 Aug. 2018, <https://www.nutraceuticalbusinessreview.com/news/article_page/Degradation_of_vitamins_probiotics_and_other_active_ingredients_caused_by_exposure_to_heat_water_and_sunlight/145924>
- Gorski, David. “Supplements: Flushing Your Money down the Toilet in Expensive Urine.” Insolence, ScienceBlogs, 19 Dec. 2013, <https://www.scienceblogs.com/insolence/2013/12/19/supplements-flushing-your-money-down-the-toilet-in-expensive-urine>