Best B12 Supplement: Benefits, Side-Effects & Product Reviews |

Best B12 Supplement: Benefits, Side-Effects & Product Reviews

It can be difficult to compare between different B12 supplements, so to make it easy we discuss everything you need to know about vitamin B12 as well as recommending some of the very best B12 supplement brands currently on available.

For those who don’t have a clear understanding of the role that vitamins and minerals play in our everyday health, it’s easy to misunderstand the importance of these essential nutrients, and often B12 is one of the most misunderstood.

Vitamins and minerals perform important actions in your body including strengthening bones, healing wounds and boosting the immune system to guard against infections and sickness.

Vitamins assist the body with everything from healthy teeth to producing energy and multiplying cells, while a lack of vitamins and minerals could lead to serious deficiencies with devastating impacts.

Most vitamins and minerals can be absorbed through healthy foods but there are several that must be supplemented by pills and liquids to ensure that enough micro-nutrients are taken in.

We explain in detail everything you could possibly want to know about B12, from the benefits, myths, side-effects and we go on to recommend what we think are the best B12 supplements that are available on the market today.

If you just want a quick overview check out the below table showing our top 3 picks. Or keep scrolling for full details.




Our Rating



Seeking Health Active B12 Lozendge

Our overall favorite


Jarrow Formulas Methylcobalamin

Great budget friendly option


Live Wise Liquid Drops

Alternative to tablets

B12 Overview

B vitamins are water-soluble and circulate through the blood. These water-soluble vitamins cannot be stored in the body and must thus be replenished regularly. The vitamin B group comprises eight vitamins that work together to regulate heart operations, support healthy brain function and metabolism and enhance central nervous system functioning and cell building.

B vitamins help the body to metabolize food and turn what we consume into energy – this also prevents weight gain as the energy lessens fat storage. Vitamin B12 shares this function with the other B vitamins but also performs a unique function in forming healthy red blood cells that are vital to nerve cell functioning.

B12 is an essential supplement especially for vegan and vegetarian diets that consume little or no meat products that hold adequate amounts of the vitamin. Similarly, B12 deficiencies are very common in people suffering from anemia and also those with Crohn’s and celiac disease.

People suffering from digestive issues, prolonged users of stomach acid-reducing drugs, those in the process of ageing and excessive alcohol consumers are also prone to vitamin B12 shortages as the vitamin cannot be absorbed properly through digestion.

Most cases of B12 deficiencies in people with healthy diets point to other indicators as the root cause of the deficiency. Malabsorption of vitamin B12 is the leading cause of low B12 levels and can be caused by either food-bound cobalamin malabsorption or pernicious anemia.

Food-bound cobalamin malabsorption is usually caused by gastric problems and requires absorption of B12 through supplements. B12 injections are the only option for those with pernicious anemia and related B12 shortages.

B12 deficiencies are usually identified by doctors after a series of benchmark tests with certain indicators. Once the test results have been obtained, B12 supplements in the form of pills, liquids or even an injection will be prescribed.

It is important to distinguish between the different types of vitamin B12 commonly available on the market.

The vitamin B12 structure comprises a cobalt ion and comes in three different forms: cyanocobalamin, methylcobalamin and hydroxocobalamin.

Cyanocobalamin is a commercially produced form of the vitamin and is best to stay away from – this synthetic type of B12 is low cost to make it more affordable but it also contains quantities of cyanide that could lead to toxicity over long periods of use.

Cyanocobalamin is not an effective form of B12 for people with pre-existing medical conditions as the body is unable to absorb the vitamin completely – the cyanocobalamin must be turned into hydroxocobalamin and then methylcobalamin to be effective and people who struggle with toxins, digestive issues, renal failure and liver problems have systems that cannot eliminate the cyanide contained in this form of B12.

The second form, methylcobalamin, is the active form of vitamin B12 and retains longer in tissues to perform its intended purpose. Methylcobalamin supplies methyl groups to the body that allow for crucial chemical reactions that maintain health to take place.

It is the best choice for people whose systems are unable to convert cyanocobalamin into methylcobalamin and can be applied with effective results to people suffering from degenerative neurological conditions including Alzheimer’s and Parkinson’s. Methyl-B12 is also useful in alleviating symptoms and side-effects of diabetes such as muscle cramps, numbness and pain.

The third form, hydroxocobalamin helps lower nitric oxide levels but is also an inactive form of B12. Although inactive, it holds the advantage of not having cyanide and requires less processing by the body to be absorbed properly – in fact, hydroxocobalamin B12 can be used as an antidote for cyanide toxicity.

Dosages can be administered less frequently as hydroxocobalamin is retained longer in the body. However, due to the lowering of nitric oxide levels that play an important role elsewhere in the body, those with digestive disturbances and pregnant women should rather use methylcobalamin B12.

Before we get on to what the best B12 supplement on the market is, let’s consider some of the common misunderstandings around this vital B vitamin.

Myths and Misconceptions Surrounding Vitamin B and B12

As with most health-related topics, there are myths and misconceptions surrounding vitamin B12 that are still doing the rounds. One of the most common misconceptions is the claim that vitamin B12 can be used as an energy enhancer to the point that it can boost endurance and improve athletic performance.

Although vitamin B12 is beneficial for raising energy levels where a nutritional deficiency is present, overdosage will not have any effect on performance level past reaching the required vitamin B12 levels.

A surprising myth is the widespread belief that vitamin B12 deficiency is uncommon and unlikely to develop, with symptoms taking several years to transpire. This is false – vegans and vegetarians with a meat-free diet could develop symptoms of deficiencies within 3 months.

Another common misconception is that the soil left on your vegetables contains essential vitamin B12 micronutrients – although this isn’t completely untrue, the amount of B12 in the soil is not sufficient for an adult’s daily recommended vitamin B12 intake and consuming unwashed vegetables could be harmful due to chemicals added to the soil.

Despite numerous claims, vitamin B12 can not be found naturally in plant-based foods such as seaweed and algae. Some plant foods such as spirulina contain vitamin B12 but this is an inactive B12 that makes no contribution to the body’s required vitamin B12 levels. Rather opt for a supplement as per your doctor’s recommended dosage guidelines.

B12 Sources and Product Types (pills, liquids, sprays, food)

These days, vitamin B12 is readily available in most health stores as a vitamin supplement. Vitamin B12 supplements can be found naturally in most meat products including fish, red meat, poultry and to lesser amounts in animal by-products such as milk, cheese and eggs.

For this reason, it is important for vegetarians, vegans and those on Paleo or gluten-free diets to monitor B12 levels and take supplements where deficiencies are present.

Vitamin B12 is present in animal products because this particular vitamin is a byproduct of microbial activity in the soil. Animals synthesize the vitamin in the gut while grazing and because they have the ability to store B12 in their cells, we are able to ingest it from meat and animal by-products.

Those following a healthy diet with regular portions of meat should have sufficient levels of B12 present. To up your intake of natural vitamin B12, eating clams, veal or beef liver can provide more than 1000% of daily recommended values. Poultry liver, mussels, trout, salmon, tuna fish and breakfast cereals fortified with B12 are other great options for additional B12 sources.

B12 vitamins can be taken orally in pills or liquid drops and can also be injected directly into muscle tissue for faster absorption. Multivitamins with methyl-B12 are most effective for vegetarians, vegans, the elderly and those presenting low levels of vitamin B12. Opt for one that dissolves in your mouth as a pill that’s swallowed may not absorb properly in the digestive system.

Sublingual methyl-B12 drops are the best choice for those suffering from gut issues that affect regular absorption of vitamin B12 in the body. Vitamin B12 which occurs naturally in food is released by hydrochloric acid and gastric protease found in the stomach – those with gut and digestive tract issues should thus rather take drops.

B12 injections are injected directly into the muscle tissue for faster absorption. This is most commonly used to treat those with severe B12 deficiencies and pernicious anemia, a condition which renders the body unable to absorb vitamin B12 from food.

The injectable form of B12 is most often hydroxocobalamin and will usually be prescribed as follows: six injections over the first two weeks and thereafter once a month for three months. Vitamin B12 injections are the strongest and most effective form of supplementation for vitamin B12 deficiencies.

B12 Benefits (Pros and Cons)

The benefits of B12 are far-reaching and improve the body’s ability to function properly in more than one area. Firstly, vitamin B12 is renowned for its properties of enabling cell and tissue growth – especially bone marrow – and producing extra red blood cells that alleviate anemia and related symptoms.

Furthermore, B12 vitamin supplements have a proven impact on improving memory, enhancing nerve regeneration and even reducing dementia, as shown in this study. Patients with pre-existing motor neuron conditions were shown to have strengthened hand grip and better neuronal functioning after regular B12 supplements.

A daily effective dose of vitamin B12 can help reduce homocystein present in the body, an amino acid which can lead to heart disease and cancer when left untreated. B12 is also indispensable in stabilizing cell membranes, allowing them to better carry hormones and therewith reduce the occurrence of hormonal imbalances.

Vitamin B12 supplements are especially beneficial to diabetic patients where effective dosage amounts have proven to improve numbness, reduce muscle cramps, relieve pain sensitivity and lower motor neuron weakness.

Methylcobalamin B12 also contains other methyl groups that enhance health in other areas which contributes to benefits of better sleeping cycles with less disturbances, the limiting of malignant cancerous cells in the body and strengthened nerve cells for better motor ability.

B12 Deficiencies and Related Symptoms (everyday and chronic)

B12 deficiencies can be difficult to pick up as symptoms often mimic other health issues including ageing, cardiovascular diseases and autoimmune illnesses. For example, symptoms of B12 deficiencies in older people including memory loss and cognitive decline are often mistaken to be signs of dementia or Alzheimer’s disease.

Additional symptoms that indicate a shortage in vitamin B12 intake include weakness, fatigue, headaches, shortness of breath and even heart palpitations. Anemia and bruising are common and often mistaken as symptoms of diabetes, while digestive issues from constipation to diarrhea, weight loss and a loss of appetite can also be ascribed to a lack of sufficient B12 levels.

Prolonged B12 deficiencies can even go so far as to cause permanent brain and nerve damage in extreme cases. Surprisingly, even infants can have shortages of vitamin B12 which would result in developmental delays, movement disorders and anemia, often paired with other serious medical conditions.

If one or more of these symptoms arise where illnesses with similar indicators have not been diagnosed, visit your physician and test for a B12 deficiency. There are several testing methods with the most common being a complete blood count (CBC) test. Results with enlarged red blood cells could indicate anemia caused by a B12 deficiency.

Homocysteine tests, MTFHR genetic tests and methylmalonic acid tests which measure B12 stored in muscle tissue are further ways of determining B12 deficiencies. Those with MTFHR genetic test results that indicate a mutation – which makes the body unable to process B12 naturally – can opt for an organic acid test which measures the body’s ability to process, methylate and functionally use vitamin B12. Ask your physician for more information regarding which test best suits your individual needs.

B12 Recommended Intake and Dosage

The recommended daily value for vitamin B12 intake for adults (ages 14+) differs between countries with 2.4 micrograms per day recommended by the US Food and Nutrition Board (FNB) guidelines, while up to 4 micrograms per day is recommended by the European Food Safety Authority.

Daily intake amounts for babies aged 0-6 months is 0.4 micrograms, while babies aged 7-12 months should get a recommended daily amount of 0.5 micrograms. Children aged 1-3 years require 0.9 micrograms daily, ages 4-8 years should get 1.2 micrograms of vitamin B12 per day and ages 9-13 require a recommended 1.8 micrograms per day.

Pregnant women require higher levels of at least 2.6 micrograms of vitamin B12 daily, while breastfeeding women should get a dosage of 2.8 micrograms per day. Physicians will often recommend vitamin B12 injections of slightly higher dosages for those with serious deficiencies.

B12 Side Effects and Overdose Effects

Research on the side effects and overdosage dangers is limited with no proven results that higher intakes are harmful. Vitamin B12 has low potential for toxicity and so far has no proven adverse effects. However, extremely high dosages of vitamin B12 will not necessarily provide added benefits of energy and red cell support beyond a certain point. Vitamin B12 is a water-soluble vitamin, which means that excess amounts will be flushed out of the body in your urine.

Side effects to the intake of vitamin B12 are rare but some cobalamin supplements have been known to interact and even interfere with other medication. Vitamin B12 reduces the effectiveness of certain antibiotics such as tetracycline, and interferes with some chemotherapy medications, bile acid sequestrants and anti-convulsants. If you are taking any medication, chronic or otherwise, check with your primary care practitioner before taking vitamin B12 supplements.

Hopefully you now know everything you need to about vitamin B12 and can make an informed choice, but here are some of our very favorites:

The Best B12 Supplement Brands:

Active B12 Lozenge With L-5-MTHF

This product contains active methylcobalamin B12 to support cellular health, cognitive health and increased energy levels. These lozenges also contain a dosage of methylfolate vital to maintaining healthy B12 levels and are easy to break into halves or quarters for adjusted dosages.

Seeking Health uses no artificial flavors, colorants or preservatives and has sweetened the lozenges naturally with xylitol and cherry flavoring. The lozenges dissolve easily and most users report a noteworthy increase in energy. This product is also suitable for those with the MTHFR gene mutation as explained above.

active b12 lozenges

No artificial colorants, preservatives or flavoring
Effective and affordable

Slow to dissolve
Not available in other flavors

Check price




Source Naturals MethylCobalamin Vitamin B-12, Cherry Flavored Sublingual, 1mg, 120 Tablets (Pack of 2)

Source Natural delivers this product as an active vitamin B12 methylcobalamin supplement that helps maintain a regular sleep-wake cycle while aiding cell growth and increasing the benefits found in the methyl groups.

Positive reviews for the product report immediate improvement in memory and being sublingual, it provides a more affordable alternative to B12 injections for those who cannot absorb the vitamin through food and pills.

source natural b12

Sublingual – can be taken by those with digestive complications
Not excessively sweet

Some reports that it doesn’t dissolve well
Strong flavoring

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MAXASORB BioActive B12 Cream- Methyl Form

Maxasorb has created a B12 Cream for easy application. This product is infused with antioxidants and has a moisturizing base, allowing for the cream to dissolve into the skin without leaving behind a layer of grease. This not only allows for easy absorption of vitamin B12 but helps moisturize dry skin and alleviate rashes from eczema and other skin irritations.

This bottle contains thirty measured applications of methyl-B12 for a one-month supply at an affordable cost. By applying a topical cream, users can save themselves from the stress of injections while ensuring that vitamin B12 supplements are effectively absorbed.

Maxasorb B12

Easy to apply
Moisturizes skin and delivers B12 supplement

Contains folic acid – shouldn’t be used by those with MTHFR gene mutation

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Vitamin B12 Liquid Drops, Sublingual, Methylcobalamin, Vegan, NON GMO

These vitamin B12 liquid drops by Live Wise are meant to be taken under the tongue, allowing for direct absorption into the bloodstream. The product boasts elevating mood and energy levels through supporting the nervous system and strengthening the immune system.

This methyl-B12 sublingual product uses an organic grape alcohol base with none of the added chemicals that are usually found in pill capsules. This bottle contains 180 servings with 5 drops delivering a 1000 microgram serving.

Live WIse B12

No additives, flavoring or sweeteners
Easy-to-use dropper and neutral taste

Not suitable for those with sensitive teeth or allergic to alcohol

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Jarrow Formulas Methylcobalamin (Methyl B12), Supports Brain Cells, 5000 mcg, 60 Lozenges

This Amazon bestseller product is a chewable type of vitamin B12 that promotes healthy homocysteine levels and offers a 5000 micrograms dose per lozenge. A definite contender for the top B12 supplement available, Jarrow’s also offers other methyl-B12 lozenges in varying dosage amounts ranging from 500mcg up to 5000mcg, with different flavors for each variant.

This product can be used by anyone and is suitable to be used by those with the MTFHR gene mutation. The lozenge is well flavored and very effective in delivering an energy boost and alleviating serious motor neuron conditions where vitamin B12 deficiencies exist.

Methylcobalamin B12

Effective and affordable
Can be used by those with MTFHR gene mutation

Contains xylitol and magnesium stearate

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