Reviews and Information for Thiamin
B Vitamin Supplements
Read our reviews of B vitamin supplements to find the best B complex, niacin, B-6, B-12, biotin, thiamin and folate, including "methyl" forms such as methylfolate. Get information about dosage, safety, and B vitamins for energy, memory, depression and more.
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Product Review
Multivitamin and Multimineral Supplements Review
Best Multivitamins -- Caution with Gummies

Product Review
Nutritional Yeast Review
Inaccurate Labeling Discovered on Most Nutritional Yeasts. Best Fortified and Non-Fortified Products Identified.

Product Review
Protein Powders, Shakes, and Meal Replacements Review
Find Out Which Protein Products Passed or Failed Our Tests

Product Review
Gluten-Free Grains Review (Buckwheat, Quinoa, Sorghum, Millet, and Teff)
31% of Gluten-Free Grains Fail Our Tests Due to Contaminants. Quinoa, Buckwheat, Sorghum, Millet and Teff Tested.

Clinical Update
4/28/2020
Early Sign of Thiamin Deficiency
Thiamin (vitamin B1) deficiency can cause lasting neurologic damage and affect heart function. It can occur with poor nutrition and as a result of taking certain diuretics. A recent case highlighted an early sign of thiamin deficiency that involves the eyes. We've added this information to the Thiamin section of the B Vitamin Supplements Review. Also see our Top Pick for thiamin and B complexes that contain thiamin. You can also get thiamin from a good multivitamin.
Product Review
Rolled Oats and Steel-Cut Oats Review
Find the Best Rolled and Steel-Cut Oats -- Beware of Unexpected Gluten.

Product Review
Farro and Bulgur Review
See How Bob's Red Mill Compares to Trader Joe's

CL Answer
Can any supplements improve or worsen symptoms of fibromyalgia?
Find out if any supplements may help improve fibromyalgia symptoms, learn which supplements do not seem beneficial, and find out if any supplements worsen symptoms.

Clinical Update
12/09/2022
Thiamin Alternative?
Is thiamin tetrahydrofurfuryl disulfide (TTFD), a derivative of thiamin, absorbed and used by the body better than thiamin itself? Find out, and learn about possible health effects, in the Thiamin (B-1) section of our B Vitamin Supplements Review.
Clinical Update
2/03/2021
Thiamin Deficiency from Bowel Disease
People with inflammatory bowel disease (such as Crohn’s or colitis) can develop thiamin (vitamin B-1) deficiency, which can lead to life-threatening brain injury, as noted in a recent review of 31 cases. Learn more about this and other causes of thiamin deficiency in the Thiamin section of our B Vitamin Supplements Review.
CL Answer
Supplements That May Be Needed When Following a Gluten-Free Diet
Find out if supplements such as folate, vitamin B-12, niacin, thiamin, iron, vitamin D, and/or fiber are needed when following a gluten-free diet. Also learn how to find gluten-free supplements on ConsumerLab.com.

Product Review
Nutrition Bars & Cookies Review (For Energy, Fiber, Protein, Meal Replacement, and Whole Foods)
Find the Best Nutrition Bar or Cookie. ConsumerLab Tests Reveals Not All Nutrition Bars and Cookies Contain What They Claim.

Product Review
Chia Seed Review — Whole, Ground, and Sprouted Seed, Seed Flour, & Supplements
Find the Best Chia Seeds, Sprouted Chia Powder, Flour, and Chia Supplements. Tests and Reviews of Chia Seeds & CL's Top Picks.

CL Answer
Which supplements may benefit people with essential tremor, and which should be avoided?
Learn about supplements used for treating essential tremor, including caprylic acid (also called octanoic acid), thiamin (vitamin B1), cannabidiol (CBD), GABA (gamma-aminobutyric acid), and branched-chain amino acids. Find out which work and which don't. Also find out which supplements and food may make essential tremors worse.

CL Answer
I take warfarin (Coumadin), an anticoagulant drug. Are there supplements I should avoid, or be taking, due to this drug?
Find out which supplements should be avoided when taking blood thinners (anticoagulants) like warfarin (Coumadin), including vitamin K, St. John's wort, and curcumin.

CL Answer
Do vitamin patches, such as for B12 or multivitamins, really work? How about those from PatchMD?
Do vitamin B12 Patches like PatchMD really work? Can you absorb vitamin B12 through patches?

Clinical Update
2/02/2024
Thiamin for Fibromyalgia?
Can taking thiamin reduce symptoms of fibromyalgia? Find out in the Thiamin section of our B Vitamin Supplements Review. Also see our Top Picks among B vitamins.
Also see: Can any supplements improve or worsen symptoms of fibromyalgia?
Clinical Update
5/04/2024
Thiamin Deficiency After Bariatric Surgery
Having bariatric surgery can lead to vitamin deficiencies in people who do not follow recommended supplementation. This was recently reported in three individuals who developed thiamin deficiency after gastric bypass surgery. Get the details in the Thiamin section of our B Vitamin Supplements Review.
Also see our Top Pick among multivitamins for people who have undergone bariatric surgery and our article about supplements to take or avoid after bariatric surgery.
Clinical Update
5/24/2017
POTS and Thiamin
A small study among people who suffer from POTS (postural tachycardia syndrome) suggested that supplementing with thiamin (vitamin B-1) may help some. For details, see the Thiamin (B-1) section of the B Vitamin Supplements Review >>
CL Answer
Are There Supplements That Help Treat POTS (Postural Orthostatic Tachycardia Syndrome)?
Find out which supplements and lifestyle changes may be helpful for people with Postural Orthostatic Tachycardia Syndrome (POTS).

Product Review
Olive Leaf Extract Supplements Review
Learn What Olive Leaf Does and the Best Brands

Product Review
Joint Health Supplements for Pets Review (Glucosamine, Chondroitin, MSM & Boswellia)
See Which Pet Supplements for Joint Health Passed Our Tests and Which Didn't!

Product Review
L-Arginine Supplements Review
Choose the Best L-Arginine Supplement. Find Out Which L-Arginine Supplement Passed CL's Tests.

Product Review
Lion's Mane and Chaga Supplements Review
Read Labels Carefully -- Many Can Mislead

Product Review
Electrolytes & Sports Drinks Review
See Which Sports Drinks, Powders, and Pills Deliver the Right Electrolytes

Product Review
Lavender and Tea Tree Essential Oils Review
Oils Tested for Authenticity and Purity

Product Review
Fruits, Veggies, and Other Greens Supplements Review (Including Spirulina and Chlorella)
Avoid Lead in Greens, Problems with Pills, and Don't Give Up Eating Whole Foods.

Product Review
CoQ10 and Ubiquinol Supplements Review
Find the Best CoQ10 and Ubiquinol Supplements and Learn How They Differ

Product Review
Mangosteen Juice and Supplements Review Article
What Are the Benefits of Mangosteen Juice and Supplements? Find Out What Mangosteen Can and Cannot Do For Your Health.

CL Answer
Do any supplements, like Nervive, help with nerve pain, like sciatica, diabetic neuropathy or postherpetic neuralgia?
Find out which supplements for nerve pain, including fish oil and alpha-lipoic acid, are effective for sciatica, diabetic neuropathy, or postherpetic neuralgia.

Product Review
Probiotic Supplements Review (Including Pet Probiotics)
Probiotics: See What They Really Contain and Our Top Picks

Product Review
Alpha-Lipoic Acid Supplements Review
Choose the Best Alpha-Lipoic Acid Supplement — See the Amounts of Active "R-Isomer" We Found

CL Answer
How do the Beyond Burger, the Impossible Burger, and a beef burger compare in terms of vitamins and minerals, and which is best?
Read our comparison of the Beyond Burger and the Impossible Burger, plant-based, meat alternative burgers. Compare nutrition, vitamins and minerals. ConsumerLab.com's answer explains.

CL Answer
What B-vitamin complex do you recommend for older people?
Vitamin B complex supplement recommendations, benefits and top rated brands for older people and all ages.

CL Answer
Which foods are a good source of B vitamins?
Find out which foods are a good source of B vitamins (like folate and B-12) and when you should take Vitamin B supplements.

Product Review
PQQ (Pyrroloquinoline Quinone) Supplements Review
Learn What PQQ Does and Which PQQ Supplements are Best

CL Answer
What is desiccated beef liver? What is it used for, and is it safe?
Description of desiccated beef liver, including what it is used for, its nutrient content, and safety concerns.

CL Answer
Do supplements help with Parkinson’s disease treatment or prevention?
Learn what has been shown with vitamins D and E, niacin, CoQ10, melatonin, creatine, SAMe, NAC, valerian, CoQ10, and CBD, as well as with coffee and the Mediterranean and MIND diets for treating and/or preventing Parkinson's disease.

CL Answer
Do any supplements or foods benefit people with Crohn's disease? Are there any supplements that should be avoided?
Find out the most common vitamin and mineral deficiencies in people with Crohn's disease, including iron, B6, B12, vitamin D, zinc and others, plus evidence for N-acetyl-glucosamine (NAG), fish oil, and curcumin.

News Release
October 17, 2024
Not All B Vitamin Supplements Contain What They Claim, According to ConsumerLab Tests
White Plains, NY, October 17, 2024 — Recent ConsumerLab tests revealed that 19% of popular B vitamin complexes and individual B vitamin supplements selected for testing contained far less, or far more of one or more B vitamins than claimed on the label.
CL Answer
What are "broad-spectrum micronutrient" supplements, and do they have greater health benefits than multivitamin/multimineral supplements?
Learn about "broad-spectrum micronutrients" and how they compare to multivitamin/multimineral supplements.

News Release
June 14, 2022
Best B Complexes, B12, and Other B Vitamin Supplements Revealed by ConsumerLab Tests: Beware of High Doses
White Plains, New York, June 14, 2022 — Recent ConsumerLab tests of over 30 popular vitamin B complexes and supplements revealed that four products contained either much less, or much more, of at least one B vitamin listed on the label.
CL Answer
Do any supplements, foods or lifestyle modifications help with brain function, like memory and cognition?
Find out which supplements help improve memory, brain function and cognition, including fish oil, some B vitamins, cocoa, and curcumin. ConsumerLab's answer explains the evidence for supplements promoted to help with brain function and cognition.

Product Review
Rhodiola Rosea Supplements Review
Do Rhodiola Supplements Help With Depression and Anxiety? Find Out and See Which Rhodiola Supplements Provide the Best Quality & Value.

CL Answer
Do any supplements help prevent or improve cataracts?
Find out which supplements may help with cataracts, including selenium and vitamins A, B1, B3, C, and E.

Product Review
Menopause Supplements Review (Soy and Red Clover Isoflavones, Black Cohosh) and Progesterone Creams
Choose the Best Menopause Supplement. Find Out Now Which Soy Isoflavone, Red Clover, Black Cohosh, and Progesterone Products Have the Active Compounds You Want!

Product Review
Choline and Lecithin Supplements Review (Including Phosphatidylcholine, CDP-Choline, and Alpha-GPC)
Choose the Best Choline Supplement. Find Out How Much Choline Popular Supplements Really Provide.

Product Review
Ginkgo (Ginkgo Biloba) Supplements Review
Choose the Best Ginkgo Biloba Supplement. Finding Real Ginkgo Isn't Easy — 60% Fail ConsumerLab's Tests of Quality.

Product Review
NAD Booster Supplements Review (NAD+/NADH, Nicotinamide Riboside, and NMN)
How Important Is Boosting NAD+ Levels? Find Out and Learn How Booster Supplements Compare.

Product Review
Ashwagandha Supplements Review
Find the Best Ashwagandha Supplement. Only 38% of Ashwagandha Products Pass Tests.

News Release
February 12, 2021
Don't Be Surprised by New Labels on Many Vitamins
White Plains, New York, February 12, 2021 — It took almost four years, but more accurate labels on vitamin and mineral supplements are finally here and consumers should not be surprised to see changes, says Tod Cooperman, M.D., president and founder of ConsumerLab.
News Release
February 23, 2017
ConsumerLab.com Reveals Best and Worst B Vitamin Supplements and Why Current Labels Often Mislead
White Plains, New York, February 24, 2017 — B vitamins and complexes are popular supplements, but labels often mislead, says a new report from ConsumerLab.com which tested, reviewed, and compared 49 supplements from the U.S.
Recalls & Warnings
November 11, 2024
FTC Sends Refunds to Customers Who Purchased Sobrenix
On November 7, 2024, the FTC announced it is mailing 56,686 checks totaling more than $536,000 to customers who bought Sobrenix, a supplement sold and marketed by Rejuvica to reduce and eliminate alcohol cravings and consumption.
CL Answer
Does Qualia Mind boost memory and mental function and is it worth cost?
Learn about the ingredients in Qualia Mind, whether or not we think the formula works and is safe, and if we think it's worth the cost.

CL Answer
Which supplements are important after bariatric surgery (i.e., weight loss or stomach-reducing surgery)? Are there any I should avoid?
Find out which supplements may help after weight loss or stomach reducing surgery, including iron and calcium, and which should be avoided.

CL Answer
Can any vitamins or minerals help prevent or reduce canker sores or cold sores?
Find out which, if any, supplements, including iron, L-lysine, monolaurin, olive leaf extract, vitamin B-12, and zinc, may be beneficial for canker sores or cold sores.

Recalls & Warnings
July 20, 2023
FTC Files Complaint Against Company Promoting “Sobrenix” Supplements for Alcohol Cravings
On July 19, 2023, the FTC filed a complaint against Rejuvica and the company owners for promoting its Sobrenix supplements, which contain ingredients such as vitamin B6, thiamin, milk thistle, Chanca Piedra, and dandelion root, to reduce and eliminate alcohol cravings and consumption.
News Release
July 27, 2016
ConsumerLab.com Helps Consumers Make Sense of the FDA's Updated Daily Values (DV) for Vitamins and Minerals
White Plains, New York, July 27, 2016 — Daily Values (DV) for certain vitamins and minerals have been changed by the FDA, as part of the agency's revised rules for nutrient and supplement facts labeling. The changes went into effect on July 26, 2016.
CL Answer
Do vitamins, minerals or other supplements lose effectiveness with exposure to high temperatures?
Are vitamins and supplements susceptible to heat? Find out if mail ordering during the summer is safe.

News Release
October 26, 2010
ConsumerLab.com reports deficiencies in some B-complex supplements and more caffeine than expected in "shot-sized" B vitamin "energy" drinks
White Plains, New York — October 26, 2010 — Tests of B vitamin supplements, including B-complexes and shot-sized energy drinks, revealed problems with the quality of 4 out of 18 products selected for review by independent testing organization ConsumerLab.com.
News Release
September 10, 2007
Tests of B-vitamins by ConsumerLab.com finds several short on folic acid — New report covers B-complexes, thiamin, niacin, B-6, B-12, biotin and folic acid supplements
WHITE PLAINS, NEW YORK — SEPTEMBER 10, 2007 — Half of the B-complex supplements recently selected by ConsumerLab.com for testing were found to lack the total claimed amounts of folic acid, an essential nutrient also known as vitamin B-9.
News Release
May 15, 2007
ConsumerLab.com finds some alpha lipoic acid supplements come up short — Improper formulation may cause ingredient degradation
WHITE PLAINS, NEW YORK — May 15, 2007 — ConsumerLab.com announced that two of eleven alpha lipoic acid supplements that it recently chose to test contained significantly less ingredient than promised on their labels.
Recalls & Warnings
July 27, 2012
Prescription and Street Drug Alternatives Found in Male Enhancement, Mood, and Sleep Supplements
On July 10, 2012, the FDA issued a warning letter to Evol Nutrition Associates, Inc. subsequent to a 2011 inspection which found a number of the company's products contained prescription and investigational drugs and were misbranded.
Recalls & Warnings
August 28, 2013
Maker of Sexual Enhancement Supplement Warned for Manufacturing Violations
On July 11, 2013, the FDA issued a warning letter to Precise Nutrition International Inc.
Recalls & Warnings
May 14, 2014
Maker of Mood, Smoking Cessation Supplements and More Warned for Violations, Drug Claims
On April 17, 2014, the FDA issued a warning letter to CDJ Holding, Incorporated, d.b.a.
Recalls & Warnings
September 05, 2014
Seller of "Nerve", "Cleanse" and Probiotic Supplements Warned for Drug Claims
On July 30, 2014, the FDA issued a warning letter to Plexus Worldwide, Inc., following a review of the company's website and product labels, which found statements made about Fast Relief, BioCleanse and ProBio5 to be drug claims.
News Release
March 30, 2005
ConsumerLab.com finds most B-vitamins of high quality but three lacking in ingredients — Test Results for 41 Products Reported Along with Information on Use
WHITE PLAINS, NY — MARCH 30, 2005 — ConsumerLab.com reported test results today for B vitamin supplements that it recently purchased in the U.S. and Canada.