The Dangers of Vitamin B Overdose

If you thought that taking as much vitamin B possible was good for you, think again.

I was reviewing the ingredients on a supplement the other day and couldn’t believe what I was seeing. The suggested dose had 14,000% of the vitamin B your body needs daily – I find this really frustrating.

That’s an absurd amount, and it can hurt you.

Yes, vitamin B is removed from your body when you urinate, but this doesn’t mean that you can take high doses and leave your body unaffected. A lot can happen before it makes its way out of your body.

Once your blood has all the vitamin B it can hold, it can be stored within your tissues at dangerous levels before being cleared out by your kidneys. Even though it’s temporary, your body will create toxic byproducts and oxidative stress during this time. When you overdose on vitamin B every day, your body won’t be able to fully reset, and you can begin developing disease.

When my patients have a vitamin B deficiency, I usually recommend that they take a trusted vitamin B supplement a few times a day. When you're low on vitamin B, you need a little more to get back to normal amounts. This isn't the same as taking a supplement that has 100 fold the amount you need every day, which is what you need to be cautious of.

This gets even worse when you’re taking synthetic vitamin B, which is used in many supplements. They aren’t the same as natural forms of vitamin B, and they’ll compete with the versions your body processes properly and disrupt your metabolism.

Staying healthy takes work. You need to pay attention to how you feel and what you’re taking to prevent accidentally hurting yourself. This is what you need to do to prevent vitamin B overdose.

Long-term Effects of Vitamin B Overdose

By the time you realize you have damage from vitamin B overdose, it can be serious and hard to treat. I can help reverse it in my clinic, but it’ll be much easier on you to prevent harm instead.

One of the most difficult effects of taking way too much vitamin B includes neurological damage. The high stress that chronic overdosing performs on your nerves can lead to neuropathy, a nerve damage disorder that causes tingling, burning, numbness, and pain in your hands and feet. It can also disturb your sleep and cause anxiety, irritability, depression, and memory issues.

One of my patients who struggles with neuropathy tested high on her B complex labs. She recently started complaining that symptoms that had came and went began to get worse again.

Liver disease can also rise from excess B3. The oxidative stress from its accumulation causes excess fat storage in the body and your mitochondria, or energy creators, to function poorly. Associated liver diseases include gout, insulin resistance, liver injury, and fibrosis.

An imbalance of B9 and B12 can even damage your DNA, leading to cancer risks. When there’s too much of either in your system, it accumulates in your plasma. They end up messing up methylation patterns, leading to cancer.

I’ve studied B complex for a while with some of my patients with methylation issues. This is the process your body uses to quality control important functions like detoxification, energy production, brain chemistry, and DNA repair. Your body adds on/off markers to your DNA, proteins, hormones, and toxins to start or stop different processes. Too much vitamin B can cause too much methylation, which leads to inflammation, anxiety, and cell overgrowth.

Heart and inflammatory conditions can form from B3 and B12 accumulation from the stress they cause in your vascular tissues. This leads to hypertension, hypotension, and increased cardiovascular events.

The list of possible conditions goes on, so it’s best to keep an eye on your ingredient lists and check for early signs now.

Just because you experience any of these conditions doesn't mean they came from vitamin B overdose. When you're struggling with symptoms, it's important to see a trusted practitioner like myself to determine and correct the cause.

Signs of Vitamin B Overdose

Take a look at all your supplements. You need to find out if you’re taking too much vitamin B, so you can correct if needed. Add up the daily percentages from each product to figure out how much you’re consuming daily.

You might be taking one supplement that has way too much vitamin B. You might be taking multiple supplements that individually have an appropriate amount, but too much when combined.

If you have a vitamin B deficiency, a qualified provider like myself might recommend higher than the daily recommended dose of vitamin B to get you back on track. Once you’re there though, it’s important to cut back to prevent overdose. This is why I recommend coming in for a functional medicine appointment whenever you feel your symptoms change.

Different types of vitamin B present different symptoms when taken in extreme doses. While these symptoms aren't exclusive to vitamin B overdose, these are the problems that can arise when your vitamin B intake crosses into the extreme.

B6 (Pyridoxine)

Too much B6 can damage your sensory neurons, leading to neuropathy. The symptoms you might feel are:

·       Numbness

·       Burning or tingling in hands and feet

·       Difficult walking

·       Photosensitivity

B3 (Niacin)

Large amounts of B3 can prevent your liver from being able to detox, causing your liver to inflame. The symptoms you might feel are:

·       Skin flushing

·       Itching

·       Nausea

·       Jaundice

B9 (Folic acid)

Too much B9 can linger in your blood. It’ll hide vitamin B deficiency and can lead to nerve damage and diminished immune function. The symptoms you might feel are:

·       Fatigue

·       Confusion

·       Anemia

B12 (Cyanocobalamin)

Excess doses can overwhelm your body and make it difficult to recycle certain metals. This leads to higher mortality and inflammatory markers. The symptoms you might feel are:

·       Acne-like skin conditions

·       Dizziness

·       Cardiovascular symptoms

Just because you're experiencing these symptoms doesn't mean that they stem from a vitamin B overdose. Whenever you start feeling new or worsening symptoms, it's important to come in so we can figure out what has fallen out of balance and correct it as soon as possible.

What You Should Do Instead

When you take supplements for vitamin B, it’s important to take well dosed, natural ingredients. Standard Process is the brand I recommend for its high quality and safe doses. Here are some of their offerings and what they will help you achieve:

·       Cat B Core: Used for heart patients and general stress

·       Cataplex B2: Calming – helpful for sleep, stress, and high blood pressure

·       Folic Acid B12: Good for energy

·       B6 Niacinamide: Good for energy and carpal tunnel

·       Whole food folate: Good for people who cannot methylate

·       Cataplex B: a bigger formula acting as a vitamin B multivitamin 

You don't need to feel nervous taking a vitamin B supplement that has appropriate doses, it's daily amounts of extreme vitamin B that can create problems for you. The important thing is to find balance with your vitamin B levels by taking the right amount for your body to work properly.

The best way to figure out how to get the exact right amounts of vitamin B is to come in for a functional medicine appointment. Take the guess work and confusion out of figuring out what you need and let a professional do it for you. I always review vitamins and supplements for you. When your labs are done, I will review so we can adjust your protocol.

There are many things that contribute to your health. When you start a new supplement, you should feel better and notice an improvement after about a week. If you feel better and start feeling worse, you should look closely at all your supplements, lifestyle, stress, and diet to see what needs adjustment.

I’ll review this all with you to determine what you need to thrive and stay safe. Schedule an appointment, and we can make sure that you’re not accidentally taking dangerous amounts of any supplement.

Sources:

1. de Kruijk JR, Notermans NC. Vitamin B6 intoxication presenting as a sensory neuropathy. Neurology. 2005;65(10):1502-1503. https://doi.org/10.1212/01.wnl.0000184513.01174.5e

2. Vrolijk MF et al. The vitamin B6 paradox: Supplementation with high concentrations of pyridoxine leads to decreased vitamin B6 function. Toxicology in Vitro. 2017;44:206-212. https://doi.org/10.1016/j.tiv.2017.06.009

3. Gdynia HJ et al. Severe sensory neuronopathy after intake of highest dosages of vitamin B6. Neuromuscul Disord. 2008;18(2):156-158. https://doi.org/10.1016/j.nmd.2007.09.009

4. Wang Z et al. Vitamin B6 toxicity secondary to daily multivitamin use: A case report. Front Neurol. 2024. PMCID: PMC10720370 https://pmc.ncbi.nlm.nih.gov/articles/PMC10720370/5. McKenney JM, Proctor JD. A review of the safety of niacin when used in the management of dyslipidemia. Am J Med. 1992;92(1A):77S-81S. https://doi.org/10.1016/0002-9343(92)90346-I6. Berge KE et al. Excess niacin metabolite 4PY links high niacin intake to vascular inflammation and atherosclerosis. Nat Med. 2024;30:388-397. https://doi.org/10.1038/s41591-023-02784-57. National Institutes of Health. Niacin (Vitamin B3)–Induced Hepatotoxicity. LiverTox Review. 2023. https://www.ncbi.nlm.nih.gov/books/NBK548176/8. Bailey SW, Ayling JE. The extremely slow and variable activity of dihydrofolate reductase in human liver and its implications for high folic acid intake. Proc Natl Acad Sci USA. 2009;106(36):15424-15429. https://doi.org/10.1073/pnas.09020721069. Mason JB et al. A temporal association between folic acid fortification and an increase in colorectal cancer rates may be illuminating important biological principles: A hypothesis. Cancer Epidemiol Biomarkers Prev. 2007;16(7):1325-1329. https://doi.org/10.1158/1055-9965.EPI-07-032910. Selhub J et al. Unmetabolized folic acid in plasma is associated with reduced natural killer cell cytotoxicity among postmenopausal women. J Nutr. 2009;139(12):2317-2322. https://doi.org/10.3945/jn.109.11339911. Flores-Guerrero JL et al. Association of plasma concentration of vitamin B12 with all-cause mortality in the general population. JAMA Netw Open. 2020;3(1):e1919274. https://doi.org/10.1001/jamanetworkopen.2019.1927412. Obeid R et al. High plasma vitamin B12 and cancer: Causality or epiphenomenon? Clin Chem Lab Med. 2016;54(4):553-565. https://doi.org/10.1515/cclm-2015-080513. Institute of Medicine (U.S.). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington (DC): National Academies Press; 1998. https://doi.org/10.17226/601514. Rios-Avila L et al. Metabolic interactions of folate and vitamin B12 and their potential role in chronic disease. Nutrients. 2015;7(7):5940-5965. https://doi.org/10.3390/nu707527015. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Tolerable upper intake levels for vitamins and minerals: Update for vitamin B6 and niacin. EFSA J. 2016;14(12):4653. https://doi.org/10.2903/j.efsa.2016.4653