Best Vitamins for Energy: B12, Iron, and More

Written by: Jillian Kubala, MS, RDN
Medically reviewed by: Ecler Ercole Jaqua, MD, MBA, DABOM

If you’re feeling drained even after a good night’s rest, you’re not alone. Many people struggle with low energy, and sometimes it’s related to deficient or low levels of key nutrients. Low levels of vitamin B12, iron, vitamin D, or magnesium in particular could contribute to fatigue and sluggishness. Fortunately, the right supplements, paired with healthy lifestyle habits, can help get your energy levels back on track.

Feeling exhausted and having low energy is a common health complaint among women. In fact, research shows that fatigue is twice as likely to affect women than men. While many factors, like a diet high in ultra-processed foods or certain underlying medical conditions, can sap energy levels, being low in certain nutrients can significantly affect how you feel.

This guide breaks down the most effective and evidence-based vitamins and mineral supplements for energy, how to incorporate them into your wellness routine safely, and which products you should skip.

Best vitamins for energy: Quick take

First things first: Taking supplements for energy isn’t a quick fix. To get the most benefits, it’s important to understand what the best vitamins for energy are, and what they can, and can’t, do to support your energy levels.

Vitamins don't directly boost energy. Technically, there’s no such thing as “energy vitamins.” Vitamin and mineral supplements don't fuel your body the way food does. They work by supporting processes that convert food into energy and helping to correct nutrient deficiencies that contribute to low energy. For example, if you’re low in vitamin B12, a B12 supplement can help restore energy levels over time by correcting the deficiency.
Expect steady progress, not instant results. Nutrient levels don’t rebound overnight. Most people need weeks of consistent supplement use to restore their nutrient levels and notice an impact on their energy. Think of supplements as a long-term support strategy for your energy rather than a quick fix.
Avoid megadoses and vague “energy blends." More isn’t always better. High doses can interfere with the absorption of other nutrients or cause side effects, and unlabeled blends make it impossible to assess safety. Also skip any nonspecific “energy boost supplement” or product made with a specialty “blend” that doesn’t disclose exact ingredients and their amounts. These products make it impossible to tell what you’re actually putting in your body.

What causes low energy: Check these factors first

Before turning to supplements for low energy, it’s important to first assess your diet, lifestyle, and any underlying medical conditions that could be affecting your energy levels.

“Low energy can result from both lifestyle factors and underlying health issues,” explains Lana Butner, ND, board-certified naturopathic doctor, licensed acupuncturist (LAc), and physician with Veracity.

Some of the most common causes of fatigue include:

Sleep debt: Poor sleep is one of the most common causes of fatigue. Even mild chronic sleep loss can drain energy levels and reduce daytime alertness.
Stress overload: Although it’s impossible to avoid all stress, chronic high stress can contribute to fatigue, exhaustion, and burnout.
Diet issues: Skipping meals, eating too few calories, or choosing highly-processed foods can zap energy and lead to energy crashes after eating.
Dehydration: Dehydration can impact your mood and energy levels, causing you to feel less alert and tired.
Underlying health issues: Many health conditions, such as hypothyroidism, depression, diabetes, and autoimmune diseases can make you feel chronically exhausted, which is why it’s so important to get regular checkups with your healthcare provider.

Some medications, such as antidepressants and pain relievers, can also contribute to feelings of fatigue.

Finally, deficiencies in key nutrients like vitamin B12, iron, vitamin D, and magnesium may also lead to low energy levels and persistent tiredness.

Since fatigue and low energy can stem from a variety of underlying causes, it’s important to see a healthcare provider before reaching for supplements.

Vitamin B12

Vitamin B12 (cobalamin) is essential for cellular energy production. Your body needs B12 to convert food into usable energy and to produce red blood cells that carry oxygen throughout the body. B12 also supports the functioning of the mitochondria, the “powerhouse” of your cells.

Low or deficient levels of B12 can significantly impact energy levels and lead to exhaustion. This is because B12 deficiency impacts multiple systems in the body. Without enough B12, your body can’t efficiently turn the food you eat into energy and can’t properly oxygenate cells, which contributes to fatigue.

Because the body can’t store large amounts of B12,consistent intake from food or supplements is important to maintain optimal levels. Some people require B12 supplements to prevent and treat deficiency.

Who may benefit from taking vitamin B12

Vegans and vegetarians (B12 is found primarily in animal foods)
People with low stomach acid or hypochlorhydria, which is common in older adults
Those with medical conditions that reduce B12 absorption, including Crohn’s disease and celiac disease
Those taking medications that impact B12 absorption, such as metformin and proton-pump inhibitors
.

Forms of vitamin B12

Vitamin B12 supplements come in several forms, including:

Cyanocobalamin: A synthetic form of B12 commonly used in supplements and fortified foods
Methylcobalamin: A naturally occurring, bioidentical form that’s readily used by the body
Adenosylcobalamin: Another natural, bioidentical form involved in cellular energy production

Some study findings indicate that methylcobalamin and adenosylcobalamin may be more bioavailable (or easily absorbed) than cyanocobalamin, a synthetic form that requires conversion to an active form before the body can use it.

Vitamin B12 dosing

The recommended daily intake of vitamin B12 is 2.4 micrograms (mcg) for adults. Pregnant women require 2.6 mcg and breastfeeding women need 2.8 mcg.

Most B12 supplements provide far more—sometimes exceeding 20,000% of the daily value—but your body only absorbs a small fraction of that amount. Depending on gut health and other intrinsic factors, your body absorbs about 50% of small B12 doses (under 2 mcg) and around 1–2% of large doses (500–1,000 mcg). This is why high doses of B12 are usually not necessary.

While most people with low B12 can improve their levels with oral supplements, those who have trouble absorbing B12 may need injections instead.

If you’re low or deficient in B12, your healthcare provider will likely recheck your levels after a few weeks to see how well the supplement is working.

Vitamin B safety

B12 is water-soluble, meaning your body excretes what it doesn't use. Because B12 isn’t readily stored in your body, it’s not associated with many side effects.

Due to its low level of toxicity, there’s currently no tolerable upper intake level (UL) established for B12. The UL refers to the maximum daily dose of a vitamin unlikely to cause harm in the general population. However, remember, your body only absorbs a small amount of B12 at a time, meaning that higher doses aren’t usually necessary.

Iron

Iron is a key nutrient for maintaining energy because it’s an essential component of hemoglobin, the protein in red blood cells that transports oxygen from your lungs to the rest of your body. Iron is also critical for energy production as it’s a part of enzymes needed for making adenosine triphosphate (ATP), the primary energy source for your cells.

Without adequate iron, your tissues don’t get enough oxygen and your cells don’t produce enough ATP, which can lead to low energy levels and exhaustion.

Iron deficiency is the most common nutrient deficiency worldwide and is much more prevalent in women than in men.

Who may benefit from taking iron

Women with heavy menstrual cycles
Pregnant women and those who are postpartum
Vegetarians and vegans (heme iron, found in animal foods, has higher bioavailability than nonheme iron, which is found in plant foods)
Those with health conditions that impair iron absorption, like celiac disease

Forms of iron

Iron supplements come in several forms, including:

Iron salts: Iron salts, like ferrous sulfate and ferrous fumarate, are some of the most common forms of iron used in supplements. Though inexpensive, iron salts have low bioavailability (meaning it’s more difficult for the body to absorb and use them), and are more likely to cause gastrointestinal side effects like constipation.
Ferrous bisglycinate: Ferrous bisglycinate is a form of iron that’s around two times more bioavailable than iron salts and is less likely to cause gastrointestinal side effects.

What you eat with iron can affect its absorption. For instance, calcium or calcium-rich foods can significantly reduce iron absorption, while pairing iron with vitamin C or vitamin C–rich foods can boost how much your body absorbs.

Iron dosing

Iron overload can be harmful, so it’s best to confirm deficiency with lab testing before starting an iron supplement. If you have low or deficient levels of iron, typical replacement regimens range from 60–200 mg of elemental iron daily or on alternate days, depending on severity and tolerance. The common recommended dose is 100–200 milligrams (mg) of elemental iron daily, split into smaller doses. Elemental iron refers to the amount of iron your body actually absorbs.

Women’s iron needs change over time. Menstruating women often need extra iron, especially if their periods are heavy. In contrast, after menopause, women who no longer menstruate typically have lower iron requirements.

However, research shows that smaller, less frequent doses, like those between 60–120 mg taken on alternate days, may improve iron absorption. After assessing your blood levels of iron and your health background, your healthcare provider will recommend a dose and schedule that works best for you. Some people that can’t absorb oral iron may require iron infusions to treat low levels.

It’s ideal to take iron on an empty stomach separate from food and other supplements.

Iron safety

Taking too much supplemental iron can be dangerous and may lead to toxicity, especially in children, so supplements should always be stored safely. High doses can cause side effects like constipation, nausea, vomiting, and dark stools. These side effects are more common with iron salt forms like ferrous sulfate.

To reduce the risk of side effects and prevent toxicity, take iron supplements only under medical supervision, and talk to your healthcare provider if you experience any issues.

Vitamin D

Vitamin D may influence energy indirectly by r egulating neurotransmitters involved in mood and supporting healthy mitochondrial function. Fluctuations in vitamin D can also modulate the function of the mitochondria, which generates cellular energy.

Studies show that being low or deficient in vitamin D is linked to fatigue and self-reported daytime tiredness. Vitamin D deficiency may also disrupt sleep, which can make you feel drained.

Who may benefit from taking vitamin D

People who live in colder climates
People with medical conditions that impact vitamin D absorption, such as celiac disease, inflammatory bowel disease (IBD), and cystic fibrosis, as well as people with liver disease and kidney failure
Older adults who don’t get enough nutrients through diet alone
People with darker skin tones

Forms of vitamin D

Unlike most vitamins, vitamin D is found in only a few foods, like fatty fish, so supplements are often the easiest way to reach and maintain healthy levels. There are two forms of vitamin D used in dietary supplements:

Cholecalciferol (vitamin D3): This is the active form of vitamin D. Most supplements use D3 derived from lanolin (from sheep’s wool), though vegan-friendly options made from lichen are also available.
Ergocalciferol (vitamin D2): This plant-based form of vitamin D is made from yeast or mushrooms. D2 is vegan-friendly but less effective at raising vitamin D levels compared to D3.

Vitamin D dosing

While the optimal vitamin D range is still debated, most experts recommend maintaining blood levels of 25(OH)D between 40–60 nanograms/milliliter (ng/mL) for overall health.

Your dose of vitamin D will depend on your blood levels as well as your age. Some people with vitamin D deficiency may require very high, weekly doses of 50,000 international units (IU), while others can be treated with daily doses of 6,000 IU. After reaching adequate levels, your provider will lower that to a maintenance dose, which is generally 2,000-4,000 IU per day to maintain healthy levels.

Vitamin D safety

Vitamin D is generally safe when taken at recommended doses, but excessive long-term intake can raise blood calcium levels and cause toxicity.

For this reason, only take high doses of vitamin D under the guidance of a healthcare provider and follow their dosing recommendations closely.

Magnesium

Magnesium is an essential mineral that powers over 300 enzyme reactions in the body, including those that create ATP. Magnesium supports better sleep by activating gamma-aminobutyric acid (GABA), a key neurotransmitter that helps calm the nervous system and regulate sleep cycles. This makes magnesium crucial for getting proper rest and feeling energized.

Magnesium deficiency is associated with symptoms like fatigue, sleep difficulties, and anxiety. Even suboptimal levels are linked with low energy.

In addition to helping you maintain optimal magnesium levels, taking supplemental magnesium has been shown to support health by reducing anxiety, lowering high blood pressure and blood sugar levels, and promoting restful sleep.

Who may benefit from taking magnesium

Anyone experiencing chronic stress, as stress can deplete magnesium
People who follow a diet low in magnesium-rich foods
Those taking magnesium-depleting medications, like metformin
People with health conditions that deplete magnesium, such as IBD and diabetes
People who have trouble sleeping or experience anxiety

Forms of magnesium

There are several types of magnesium used in supplements, some of which are better absorbed than others. Here are just a few of the most common forms:

Magnesium oxide: This magnesium salt may help with issues like headaches and constipation, but it’s poorly absorbed compared to other forms. It’s also been linked to side effects such as diarrhea.
Magnesium citrate: Magnesium citrate (included in Metabolism Ignite) is more easily absorbed than magnesium oxide and less likely to cause digestive side effects.
Magnesium glycinate: Magnesium glycinate, a compound of magnesium and the amino acid glycinate, is highly absorbable, gentle on the stomach, and effective for correcting low magnesium levels.

Magnesium dosing

Adults typically need between 310–420  mg of magnesium daily from food and supplements. Supplements can help you meet this target, especially if your diet is low in magnesium-rich foods.

The tolerable upper intake level (UL) of 350  mg per day applies to supplemental magnesium only,, not food). Higher doses can be used safely under medical guidance for specific conditions including high blood pressure, anxiety, and high blood sugar.

Magnesium safety

Magnesium supplements are generally considered safe and aren’t usually linked to dangerous side effects. However, excessive intake can cause magnesium toxicity, a rare but serious condition that may lead to low blood pressure, irregular heartbeat, or even death.

Though magnesium toxicity is usually caused by accidental overdose of magnesium-containing products like antacids and laxatives, it’s best to stick to recommended doses and only use high-dose magnesium under medical supervision.

Other helpful supplements for energy

While B12, iron, vitamin D, and magnesium play central roles in maintaining energy, other supplements may also be helpful in some cases. As always, it’s best to check your nutrient levels and optimize your diet and lifestyle, and check with your provider, before adding anything new to your routine.

B-complex: In addition to B12, taking other B vitamins involved in energy metabolism, such as B1 and B2, can help support overall energy levels. Veracity’s Metabolic Multivitamin contains all 8 B-complex vitamins in absorbable forms.
Coenzyme Q10 (CoQ10): CoQ10 supports mitochondrial energy production and may help reduce fatigue in people taking statins or with specific mitochondrial disorders that may deplete CoQ10 . Butner recommends a dose between 100-200 mg daily.
Omega-3s: Taking omega-3s may help boost energy by reducing inflammation and supporting mood, helping you feel more energized overall. For example, high-quality omega-3 supplements provide around 1,000–2,000 mg per serving. Veracity’s Omega 3 Super+, provides 1,900 mg of omega-3s per dose.
Creatine: Creatine may help reduce fatigue in some people, such as women experiencing fatigue during their menstrual cycle. Creatine supports energy production in your muscles, making it useful for improving endurance and overall vitality.

Energy supplements to skip

Not all energy supplements deliver what they promise. When shopping for supplements, be cautious of:

Megadose B blends: Excessive doses of B vitamins aren’t necessary for most people and can sometimes cause side effects such as flushing and low blood pressure.
Energy formulas that aren’t labeled clearly: When choosing energy supplements, avoid proprietary blends that don’t include ingredient amounts. Look for clear labels that list each ingredient and how much of it is included, so you know what you’re taking (and have a better idea of whether or not it’ll be safe and effective).
Sugar-loaded gummies: Gummy supplements can contain several grams of added sugar per serving, which can spike blood sugar and damage your teeth over time.
Multiple overlapping supplements or multivitamins: Taking too many similar products simultaneously can push vitamin and mineral totals above safe upper limits.

Buying guide: Choosing vitamins for energy and tiredness

“Quality is key when choosing supplements,” explains Butner. She recommends opting for high-quality, third-party tested supplements whenever possible to ensure purity and potency.

Third-party certification: Whenever possible, buy supplements that are third-party tested by organizations such as the United States Pharmacopeia (USP) or National Sanitation Foundation (NSF). Third-party testing helps verify that supplements contain the ingredients listed on the label and are free from harmful contaminants.
Clearly listed doses and forms: As mentioned above, choose products with clearly listed ingredient amounts and forms, and avoid anything that’s not transparently labeled.
Fit for dietary preferences and allergies: Make sure the product is safe for your dietary preferences and needs, including potential allergens (soy, wheat, etc.).
Serving size and cost: Some supplements require multiple capsules per dose, which may not suit everyone (e.g. those who don’t like swallowing pills) and can add up in cost over time.

How to use supplements for energy safely

To use supplements for energy safely, Butner shares the following tips:

Work with your doctor: “It’s always best to consult with your healthcare provider before starting any new supplements to ensure they’re appropriate for your specific needs and won’t interact with medications,” she explains.
Assess your levels: Whenever possible, Butner recommends getting your nutrient levels tested before taking supplements to avoid unnecessary or excessive intake.
Stick to safe doses and combinations: Follow recommended doses and stay safe by learning about possible interactions between supplements and medications.
Adjust the timing: Different supplements work best at certain times. For example, take iron on an empty stomach away from other supplements or medications, and magnesium in the evening to support restful sleep.
Pair them with healthy habits: Remember that supplements can’t stand in for a healthy diet, exercise routine, or proper sleep. “Supplements should enhance a healthy lifestyle, not replace it,” explains Butner.

Non-supplement habits that support energy levels

Supplements can fill nutrient gaps, but lifestyle habits create the foundation for optimal, lasting energy levels. In addition to a targeted supplement routine, focus on nourishing your body with balanced meals, moving regularly, and getting enough sleep. Here are a few quick tips.

Morning daylight and short walk: The combo of natural light, fresh air, and gentle movement sets your internal clock for better energy throughout the day.
Protein and fiber at every meal: Eating protein and fiber with every meal (and snack, if possible) supports steady blood sugar and helps prevent energy dips.
Hydration: Hydration needs vary, but The National Academy of Medicine recommends a total daily water intake from beverages and water-rich foods of about nine (8-oz.) cups for women and 13 (8-oz.) cups for men.
Prioritize sleep: Aim for seven to nine hours per night and stick to consistent bedtimes and wake times.
Exercise: Work in consistent daily cardio, such as brisk walks, and at least two days of resistance training a week.

Working with a healthcare provider on energy levels

If fatigue persists, it’s essential to talk to your healthcare provider. “Persistent fatigue can indicate conditions such as thyroid issues, anemia,or other metabolic or hormonal imbalances. “Addressing the root cause early helps restore energy more effectively and prevents long-term complications,” says Butner.

If you’re experiencing fatigue along with symptoms such as shortness of breath, unintended weight changes, or persistent low mood, see your doctor as soon as possible. They can order lab work and other medical tests to help rule out underlying health issues.

Key takeaways

Low or deficient levels of nutrients like B12, iron, vitamin D, and magnesium can sap energy and lead to fatigue.
Supplementing with specific nutrients can support energy by helping to restore nutrients to proper levels.
Testing is important—lab work can identify deficiencies and guide safe, effective supplement choices.
Supplements can help fill gaps, but can’t take the place of a healthy lifestyle or diet.
Avoid taking multiple supplements at once or large doses without medical guidance.

Frequently Asked Questions (FAQs)

What vitamin gives you the most energy?

The best vitamins for energy vary from person to person and depend on your individual nutrient levels. Supplements like vitamin B12 and iron can help boost energy by addressing underlying deficiencies that contribute to fatigue.

What vitamin is best for fatigue?

It depends on what your body needs. Low levels of vitamin B12, iron, vitamin D, or magnesium can all cause fatigue. Correcting these deficiencies with targeted supplements can help restore your energy.

How can I quickly boost my energy levels?

Eating an energizing meal or exercising—even a brisk walk— can boost your energy right away. Supplements are more of a long-term strategy for energy support, and typically take several weeks of consistent use to make a noticeable difference.

What vitamins am I deficient in if I'm always tired?

Common culprits that cause tiredness include low vitamin B12, iron, and vitamin D. To officially confirm low levels of any vitamins or nutrients, see your doctor for lab tests.

Why am I so tired and sleepy all the time?

Fatigue can be caused by multiple factors, including poor sleep, stress, health conditions like hypothyroidism, and nutrient deficiencies.

What can I drink to boost my energy?

Hydration is key for sustained energy. Caffeine can give you a quick boost, but it’s essential to stay hydrated by drinking plenty of water throughout the day.

Jillian Kubala, MS, RDN November 13, 2025

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