Nature Made Vitamin B1 100 mg Review

Nature Made Vitamin B1 100 mg Tablets is a single-ingredient dietary supplement providing 100 mg of vitamin B1 per tablet, listed on this page as item number 1281. Vitamin B1, also known as thiamin, is part of the family of B vitamins. According to the page, it helps support cellular energy production and normal nervous system function. The product is presented in the Energy category, and the page marks it with a tablet form icon and a 100 mg strength label. The benefits section lists two main points: it helps convert food into cellular energy, and it helps support normal nervous system function. The brand describes itself as the number one pharmacist recommended letter vitamin brand, based on a U.S. News and World Report and Pharmacy Times survey of pharmacists recommending this category. The bottle carries a United States Pharmacopeia USP Verified mark, which the page explains means USP has tested and verified the ingredients, potency and manufacturing process for dietary supplements. The product facts state that it is sourced from high quality ingredients. Labelled claims include gluten free, no artificial flavors, no color added and no preservatives. The suggested use is one tablet daily with water and a meal for adults. The page advises that anyone taking medication, including anticonvulsants, should consult a physician before use, and that potential drug-nutrient interactions may occur. The nutrient shortfall section explains that thiamin plays a role in converting food into cellular energy and supports nerve function, and it notes that the best food sources of thiamin include pork, whole or enriched grains, organ meats, red meats, yeast, nuts, sunflower seeds, peas, milk, cauliflower, spinach and legumes. The count shown is 100 tablets per container with a serving size of one tablet. The page indicates the product is discontinued and that stock is low, and it shows a one-time purchase price alongside a subscribe and save option with a ten percent discount and free shipping. Statements on the page have not been evaluated by the Food and Drug Administration, and the product is not intended to diagnose, treat, cure or prevent any disease.

Product Focus: EnergyAlso covers:BrainMetabolism
Tier ⓘ
Tier 3
Tier 3 · Reviewed. Strong review agreement, with limited or early support from human studies. Tiers run from 1, the strongest evidence, to 5. How we grade →
Evidence ⓘ
68 /100
How strongly the evidence says this product works: human studies count most, then real reviews, then our biohacker panel.
Positive Reviews
91% of 911
Biohacker Mentions
7 of 10
Cost per month
$2

Study, Trial or Testing Result Summary

Members Only28 human studies · 10 improved

1 of these 28 human studies gave the ingredient by injection, not by mouth.

28 human studies10 improved17 no effect16,094 people studied

Thiamine, or vitamin B1, is the main ingredient here at 100 mg a day, well above the 10 mg that helped in one study. Results for energy are mixed and point to benefit mainly in people who are low in thiamine or have certain long-term illnesses. In older women with mildly low thiamine, 10 mg a day for six weeks lowered fatigue and improved well-being and appetite compared with placebo [1]. In people with inflammatory bowel disease and severe fatigue, very high doses of 600 to 1800 mg a day cut fatigue clearly over four weeks [2], and a small pilot without a placebo group reported similar relief [3]. Other studies found no benefit. The same high dose did not beat placebo in people with a liver disease [4], 300 mg a day for twelve weeks did not change fatigue in bowel disease [5], and a related compound, sulbutiamine, did no better than placebo for fatigue after an infection [6]. The tablet also holds 34 mg of calcium, far below the 1000 mg used in studies, and calcium itself showed little support for energy [7][8]. Animal and cell studies are never counted.

See all 28 studies →Hide the studies

Review Totals and Summary

Members Only911 reviews · 91% positive
911 reviews · Walgreens 354 · Swanson Vitamins 289 · Walmart 229
91% positive4% neutral5% negative

Across the stores that sell it, Nature Made Vitamin B1 100 mg carries about 622 ratings, and buyers are mostly happy. Most reviews give 4 or 5 stars, with praise centered on price, brand trust and small, easy-to-swallow tablets. The few complaints are about delivery and low stock, not the tablets themselves. **What buyers say it did for them:** Reports of benefits are brief and personal. One buyer started taking it after gastric bypass surgery and says "they work well." Another buys it for a wife with MS and calls the tablets "perfect." One person uses it "to improve my memory," and a Walgreens summary mentions someone saying it calms their foot nerves. One reviewer doubted that a very high dose is needed, since most of the excess leaves in urine, but did not think it could do harm. Many reviews are general satisfaction with no specific effect described. **What buyers complain about:** The complaints concern buying, not the product. One buyer had delivery "delayed several times" and says they will not buy from that supplier again. Another got the wrong item, writing that a different product "came" instead. A Walgreens shopper reports "low stock" at their store. No review of the tablets complains about quality. **Taste, smell, pill size and form:** The wife-with-MS reviewer says the tablets spare her "the awful taste of this supplement" and the belching it seems to cause. The 100 mg strength also means she does not have to cut pills. The Walgreens summary says five reviewers describe the tablets as nice and small, which suggests they are easy to swallow. The Walmart page notes a bottle count of 100. **Value for money:** Price is the most common theme. One review says "Excellent price and good quality," and another says the price is lower than a prescription. A Walgreens shopper likes that the store "often has buy 1 get 1 free." The Walgreens summary says six reviewers highlight price. The Walmart summary says quality is on par with pricier supplements. The Nature Made site's own page shows top scores for value. **Who it seems to suit and who it did not:** It suits people who need a B1 supplement and want a 100 mg tablet. One buyer says it is "the only brand I buy," and another says none of the other brands "compare to these." The site's reviewers include daily users aged 45 to 65 or older. No reviewer says the tablets themselves did not suit them. The unhappy buyers had problems with a seller, a delivery or an order mix-up. Shoppers who depend on a local Walgreens may find stock thin, so ordering ahead or using pickup may help. Reviews of other forms of the product, such as gummies, capsules and powder, were left out, and this summary covers the tablets only.

Biohacker Summary

Members Only7 of 10 recommend it
7 of 10 biohackers on our panel recommend it

Nobody on the panel spoke about vitamin B1, the main ingredient here, so there is nothing from the group to report on it. All ten spoke only about calcium, a smaller ingredient in this product, and their views are mixed. Several recommend it for bone health, with one suggesting 1,000 to 1,200 milligrams a day from food or supplements, and one takes a calcium and magnesium pill, but others prefer food sources like sardines and leafy greens and caution that supplements may raise heart or kidney risks, and one told people to stop calcium supplements.

See all 10 biohackers →Hide the biohackers
  • Dr. Eric Berg · Calcium · warns
    • 25 Oct 2026 · warns · YouTube ↗
      Warns that bone loss cannot be fixed with just calcium, as bone is primarily collagen with other essential minerals.
    • 10 Oct 2026 · warns · Podcast ↗
      Dr. Berg includes calcium carbonate among the synthetic supplements to avoid.
    • 3 Oct 2026 · warns · YouTube ↗
      Warns against calcium carbonate, also known as limestone, stating that while it lowered hip fractures in a study, it also increased kidney stones and is not good for arteries, requiring the body to work hard to use it.
    • 27 Sep 2026 · neutral · X ↗
      Notes that tannins in tea bind calcium, blocking its absorption.
    • 10 Sep 2026 · neutral · Facebook ↗
      Indicates that horizontal thin white lines near the base of the nails are indicative of low calcium.
    • 4 Sep 2026 · warns · Facebook ↗
      Warns that calcium carbonate can build up in the arteries and kidneys and increase the risk of a heart attack.
    • 3 Sep 2026 · neutral · Facebook ↗
      Dr. Berg mentions that fermented dairy contains vital nutrients, including calcium.
    • 3 Sep 2026 · neutral · Instagram ↗
      States that calcium and magnesium are intrinsically linked and work in combination with vitamin D to support the body's calcium balance.
    • 17 Aug 2026 · neutral · Facebook ↗
      Explains that calcium triggers muscle contraction, while magnesium is needed to relax the muscles afterward.
    • 9 Aug 2026 · warns · YouTube ↗
      Warns that too much calcium can cause high blood pressure by causing arterial contraction.
  • Siim Land · Calcium · neutral
    • 30 Sep 2026 · neutral · X ↗
      Lists dairy and sardines as sources of Calcium.
    • 14 Aug 2026 · neutral · X ↗
      Notes that Boron reduces calcium/magnesium loss.
    • 14 Feb 2026 · recommends · TikTok ↗
      Recommends a high calcium intake for bone health.
    • 28 Dec 2025 · warns · YouTube ↗
      Places calcium supplementation in the 'bad tier' due to its association with increased cardiovascular events, recommending dairy or bones as easier ways to get calcium, though it can be useful for postmenopausal women with low bone density.
    • 6 Oct 2025 · neutral · YouTube ↗
      Mentions that eating enough calcium matters for bone density, but states that it alone won't transform bone density.
    • 8 Sep 2025 · warns · TikTok ↗
      Warns that calcium is linked to a higher risk of heart disease, though people with low calcium status and intake can take it safely.
    • 8 Sep 2025 · warns · YouTube ↗
      Warns that calcium supplements increase the risk of heart disease by raising blood calcium levels too high, leading to hypercalcemia and more calcium being stored in the arteries, and also increase the risk of arrhythmias.
    • 16 Aug 2025 · warns · YouTube ↗
      Warns against calcium supplementation for most people due to its association with increased cardiovascular events, but notes it can be useful for postmenopausal women with low bone density who don't consume dairy.
    • 16 Aug 2025 · neutral · Podcast ↗
      Discusses Calcium as a supplement.
    • 14 Jul 2025 · recommends · YouTube ↗
      Recommends consuming calcium from dairy, tofu, leafy greens, and bones, as it is a key nutrient required for ATP synthase in mitochondrial energy production.
  • Thomas DeLauer · Calcium · neutral
    • 18 Sep 2026 · neutral · Facebook ↗
      Notes that milk contains 120mg of calcium, while sardines contain 351mg, highlighting a 3x difference.
    • 12 Aug 2026 · recommends · YouTube ↗
      Recommends getting calcium, along with vitamin D, zinc, and magnesium, from foods like sardines, as they are important for inflammatory pathways in the gut.
    • 30 Jun 2026 · neutral · YouTube ↗
      Explains that eating sardines with their soft bones provides a serious hit of calcium, which is a perfect combination for bones and may contribute to satiety.
    • 19 Jun 2026 · neutral · YouTube ↗
      Mentions that magnesium and calcium should not be taken together as they cancel each other out.
    • 13 Jun 2026 · warns · YouTube ↗
      Tries to get multivitamins without calcium or with a low amount, as he believes supplemental calcium impacts the absorption of other vitamins and minerals and is not as beneficial as hyped. He cautions against it for most people due to the risk of coronary artery calcification.
    • 12 Jun 2026 · recommends · YouTube ↗
      Recommends getting calcium from dairy sources like milk, yogurt, kefir, and cheese in the morning to support neurotransmitter synchronization crucial for deep and REM sleep, noting that low dietary calcium is linked to insomnia.
    • 20 May 2026 · warns · YouTube ↗
      Warns that calcium competes with magnesium for the same absorption channels, advising to separate magnesium intake from calcium supplements or dairy by at least an hour or two.
    • 2 May 2026 · recommends · YouTube ↗
      Recommends providing the body with adequate dietary calcium, not a calcium supplement, to ensure a clean, strong spark for efficient insulin release.
    • 10 Apr 2026 · warns · YouTube ↗
      Warns that calcium and magnesium should not be taken together as they cancel each other out, though some products use delayed absorption to mitigate this.
    • 22 Mar 2026 · warns · YouTube ↗
      Warns that most people consume too much calcium relative to magnesium, which can disrupt the balance needed for proper bodily function, comparing it to an electrical circuit.
  • Dr. Mark Hyman · Calcium · recommends
    • 20 Aug 2026 · recommends · YouTube ↗
      Notes that calcium is in bones but is also essential for nerves, muscles, and the heart, and low levels can affect muscle function and heart rhythm.
    • 17 Jun 2026 · neutral · YouTube ↗
      States that green leafy vegetables are great sources of calcium.
    • 3 Nov 2025 · neutral · Podcast ↗
      Notes that calcium needs are lower than advertised and that stress, soda, and excess sugar can drive calcium loss.
    • 17 Sep 2025 · warns · YouTube ↗
      Does not prescribe calcium supplements at all, teaching people to get it from whole foods instead, because calcium supplements don't work for building bones or preventing fractures, and it's bone quality, not density, that matters.
    • 14 May 2025 · warns · YouTube ↗
      Warns that acid blockers inhibit calcium absorption.
    • 2 Apr 2025 · recommends · YouTube ↗
      Lists calcium as another important nutrient that people can be tested for and measured.
    • 12 Mar 2025 · warns · YouTube ↗
      States that high doses of calcium supplementation in the elderly were not really impacting bone density, as osteopenic patients still became osteoporotic.
    • 29 Nov 2024 · warns · YouTube ↗
      Warns that meds (meds) impair the absorption of calcium, which increases the risk of hip fractures and osteoporosis.
    • 15 Nov 2024 · recommends · YouTube ↗
      Recommends calcium citrate, about 600 milligrams a day, for bone health, noting that much can also be obtained from diet through leafy greens, sesame seeds, tahini, and chia seeds.
    • 27 Sep 2024 · warns · YouTube ↗
      Dr. Hyman notes that while calcium deficiency is not common in terms of blood levels, insufficient intake can lead to osteoporosis as the body pulls calcium from bones. He advises caution with calcium supplementation due to potential heart issues.
  • Dr. Rhonda Patrick · Calcium · neutral
    • 29 Jun 2026 · neutral · Facebook ↗
      Mentions that kale delivers calcium, a micronutrient many diets fall short on.
    • 9 Jan 2026 · neutral · Facebook ↗
      Notes additional gaps in calcium.
    • 3 Jul 2024 · warns · YouTube ↗
      Reports that alcohol use disorder is associated with a 20-50% greater prevalence of Calcium deficiency.
    • 9 Oct 2015 · neutral · YouTube ↗
      Around 38% doesn't meet the requirement for calcium.
    • 11 Feb 2015 · uses · YouTube ↗
      Takes a calcium-magnesium pill because he believes people tend to be short of both and that the body cares about the ratio of these similar molecules.
    • Date not recorded · recommends · Website ↗
      States that 1,000 milligrams of calcium per day is the recommended intake for bone density, and supplementation is an option if this requirement is not met.
    • Date not recorded · uses · Website ↗
      Takes a calcium, vitamin K2, and vitamin D combination supplement in the morning, providing about 600 mg of calcium and another 1,000 IUs of vitamin D.
    • Date not recorded · neutral · Website ↗
      Dr. Rhonda Patrick discusses calcium needs.
  • Dave Asprey · Calcium · neutral
    • 16 Jun 2026 · neutral · Facebook ↗
      Notes that when energy intake is too low for training demand, nutrient intake often falls short, especially for calcium, which is associated with reduced bone health.
    • 12 Jun 2026 · neutral · Instagram ↗
      Explains that calcium provides the raw material for bones, but it isn't a standalone input and needs a whole system to be effective.
    • 12 Jun 2026 · neutral · X ↗
      Notes that people take calcium for their bones.
    • 14 May 2026 · warns · YouTube ↗
      Warns that taking calcium without vitamin D, A, and K2 can lead to calcium going into tissues, causing bone spurs and other issues, and recommends a two-to-one ratio of calcium to magnesium.
    • 30 Dec 2025 · recommends · YouTube ↗
      Recommends taking calcium citrate during a high oxalate meal to bind the oxalate in the gut.
    • 21 Oct 2025 · neutral · YouTube ↗
      Notes that people often take calcium for bone health.
    • 5 Aug 2025 · warns · YouTube ↗
      Believes calcium supplements are overrated, as most people need more vitamin K2 and vitamin D instead.
    • 2 Aug 2024 · recommends · YouTube ↗
      Advises taking iron and calcium separately because they will bind together.
    • 22 Apr 2024 · uses · YouTube ↗
      Takes extra calcium to help deal with the burden when eating chocolate or anything with higher levels of oxalates.
    • 25 Jan 2024 · neutral · YouTube ↗
      Discusses calcium citrate as a counter to oxalate crystals, specifically when consumed through dairy, but questions if it's the primary form of calcium in dairy.
  • Ben Greenfield · Calcium · neutral
    • 9 May 2026 · neutral · YouTube ↗
      Is considering whether he needs a calcium supplement because lead can displace calcium in bones, affecting bone strength.
    • 6 May 2026 · neutral · X ↗
      Mentions calcium as a common deficiency.
    • 12 Apr 2026 · recommends · Facebook ↗
      Recommends adequate intake of calcium for bone strength.
    • 13 Feb 2026 · uses · YouTube ↗
      Is using calcium chloride mixed with PRP before injecting for the P-shot.
    • 22 Nov 2025 · stopped · YouTube ↗
      Advises people to stop taking calcium supplements as part of the Root Cause Protocol.
    • 21 Aug 2025 · warns · Facebook ↗
      Warns that in high doses, calcium without the right cofactors can raise cardiovascular risk by contributing to arterial calcification instead of bone strength, and may increase the risk of osteoporosis.
    • 3 Apr 2025 · warns · YouTube ↗
      Explains that 10X separates calcium and zinc into different micro beads, releasing them at different rates and locations in the digestive tract to prevent competition and optimize absorption.
    • 26 Dec 2024 · neutral · TikTok ↗
      Covers calcium as a key supplement for kids.
    • 11 Apr 2024 · warns · YouTube ↗
      Warns of calcium deficiency on a carnivore diet, as there is not an appreciable amount in meat, and recommends eating fish with bones or taking a calcium supplement or bone mineral matrix.
    • 17 Oct 2020 · warns · YouTube ↗
      Notes that excess calcium intake can contribute to calcium buildup in the arteries.
  • Peter Attia · Calcium · recommends
    • 9 Jul 2025 · recommends · YouTube ↗
      Recommends calcium as one of the 'big three' micronutrients for bone health, suggesting a daily intake of 1,000 to 1,200 milligrams, which can be supplemented with calcium carbonate or calcium citrate.
    • 6 Jul 2025 · neutral · YouTube ↗
      Explains that bone is 50 to 70% mineral, predominantly calcium, and that virtually all of the body's calcium is contained within bone, making bone important for calcium homeostasis.
    • 22 Oct 2024 · recommends · YouTube ↗
      Recommends calcium for bone health, stating that teenagers probably need about 1000 milligrams a day.
    • 21 Oct 2024 · recommends · YouTube ↗
      Discusses bone acting as a reservoir for calcium and how resorption and formation release calcium into the blood when needed.
    • 18 Jul 2022 · neutral · YouTube ↗
      Notes that bone is 50 to 70 percent mineral, with calcium being the predominant mineral, and virtually all of the body's calcium is contained within bone.
    • 26 Oct 2020 · recommends · YouTube ↗
      Recommends getting about a gram of calcium a day from organic bone meal, which provides calcium hydroxyapatite, the form humans are meant to consume.
    • 12 Jan 2020 · neutral · YouTube ↗
      Suggests that calcium is one of the other signals involved in regulating mitochondrial number, beyond AMPK activation.
    • 7 Jan 2020 · warns · YouTube ↗
      States that in postmenopausal women not on estrogen, calcium and vitamin D have no protective effect against hip fracture because the problem is not the shell of the bone, which is fed by calcium and vitamin D, but the internal girder network.
    • Date not recorded · neutral · Website ↗
      Notes that compelling evidence links calcium to reduced risk of osteoporosis, which can impact mortality from specific causes.
  • Bryan Johnson · Calcium · recommends
    • 5 Jun 2025 · recommends · YouTube ↗
      Recommends calcium as a mineral that, along with phosphorus, magnesium, and boron, is deposited to fortify the bone structure after the collagen scaffold is in place.
    • 12 May 2025 · recommends · YouTube ↗
      Agrees that a little extra calcium is probably okay, especially for women, to really hit home for bone mineral density.
    • Date not recorded · recommends · Website ↗
      Recommends prioritizing calcium intake for postmenopausal women to help maintain bone density and reduce the risk of osteoporosis.
    • Date not recorded · uses · Website ↗
      Bryan Johnson takes Calcium daily as part of his Longevity Mix, which supports healthy bones and teeth.
    • Date not recorded · recommends · Source ↗
      Recommends continuing with calcium to support bone health during the follicular phase.
  • Andrew Huberman · Calcium · neutral
    • 6 Mar 2023 · neutral · Podcast ↗
      Discusses "hard water" and the role of magnesium and calcium in cardiovascular health.
    • Date not recorded · recommends · Website ↗
      Adequate intake of calcium is vital for bone health.

RAL Summary

Members OnlyTier 3 for Energy

Tier 3 rests on 911 reviews with 91 percent positive, while study support for thiamine and energy is thin and mixed, helping mainly people who are low in it or have certain illnesses [1][2].

  • Calcium: trace amount

Where the evidence disagrees: 17 of the 28 human studies found no effect.

More Details

Members OnlyBody systems · Combine with · Possible side effects

Body systems: Nervous system, Metabolic system

Combine with: For energy metabolism and nerve support, thiamine pairs well with other B vitamins such as a B-complex (B2, B3, B6, B12, folate) since they work together in cellular energy pathways. Magnesium is also required as a cofactor for thiamine-dependent enzymes, and alpha-lipoic acid works alongside thiamine in mitochondrial metabolism and nerve health. If the real goal is fast heartburn relief, look instead at calcium carbonate or magnesium/aluminum hydroxide antacids, alginate (sodium alginate) formulas, or short-term options like H2 blockers, and discuss persistent or frequent symptoms with a healthcare provider. For longer-term digestive comfort, consider DGL licorice, zinc-carnosine, or aloe vera, but check with a clinician if you take medications.

Possible side effects: No major side effects reported; high-dose thiamine was described as safe in one trial.

Supplement Facts

Thiamine 100 mg · Calcium 34 mg
Supplement Facts
Serving Size 1 Tablet(s)
Amount Per Serving% Daily Value
Thiamine100 mg
Calcium34 mg

Other ingredients: Cellulose Gel, Maltodextrin, Croscarmellose Sodium, Magnesium Stearate.

Directions: Suggested use: Take one tablet daily with a meal. For easier swallowing, take with water before and during ingestion.

Label source: NIH label database · Report a label change

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Our articles on this subject

Graded November 4, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.