Vitamins for Energy: Which Ones Help With Tiredness

The vitamins and minerals most linked to energy are vitamin B12, iron, vitamin D and magnesium, but they mainly help when your level is low. Vitamins do not stimulate you the way caffeine does. Your body needs them to turn food into usable energy and to carry oxygen, so running short of one can leave you tired, weak or foggy, and correcting the shortfall is what makes the difference. This guide covers which vitamins matter most for tiredness, who is most likely to run low, what the research shows, and how to choose one safely.

It is educational, not medical advice.

Key Takeaways

• Vitamin B12: low levels can cause tiredness and weakness, and people who eat little or no animal food, many older adults and people on some medicines are more likely to run low (NIH ODS).
• Iron: in 198 tired women with low iron stores but normal hemoglobin, 12 weeks of iron cut fatigue scores by about 48%, against 29% on placebo (Vaucher et al., 2012).
• Vitamin D: in 120 tired adults with low vitamin D, 72% of those given vitamin D3 reported less fatigue, against 50% on placebo (Nowak et al., 2016).
• B vitamins, vitamin C, iron, magnesium and zinc all play a part in making energy in cells, and fatigue can follow when intake falls short (Tardy et al., 2020).
• Test before you guess: a simple blood test can show whether you are low, and more is not better once your level is normal.

Do Vitamins Give You Energy?

Not directly. Vitamins contain no calories, so they are not a source of energy in themselves. What they do is help your cells release energy from food, build red blood cells and carry oxygen. A review of the biochemistry found that B vitamins, vitamin C, iron, magnesium and zinc each have a role in these steps, and that mental and physical fatigue can appear when status is not adequate (Tardy et al., 2020).

That is why the trials with clear results enrolled people who were tired and low in the nutrient being tested.

Our guide to vitamin B12 benefits looks at B12 in more detail.

The Best Vitamins for Energy and Tiredness

Nutrient	Who is more likely to run low	Adult daily amount (NIH)
Vitamin B12	Vegans and vegetarians, older adults, people taking metformin or acid reducers, after some stomach surgery	2.4 mcg
Iron	Women with heavy periods, pregnant women, frequent blood donors	18 mg for women 19 to 50; 8 mg for men
Vitamin D	Older adults, people with darker skin, people who get little sun	600 IU (15 mcg) to age 70; 800 IU (20 mcg) after
Magnesium	Older adults, people with digestive problems or heavy alcohol use	310 to 320 mg for women; 400 to 420 mg for men

1. Vitamin B12

Vitamin B12 helps keep your blood and nerve cells healthy. Low B12 can cause tiredness, weakness, numb or tingly hands and feet, confusion and poor memory. B12 is found naturally in animal foods, so people who eat little or none are more likely to run low, as are many older adults and people who have had some types of stomach or intestinal surgery. Acid-reducing medicines and metformin can reduce how much you absorb (NIH ODS). Learn more on our methyl B12 (methylcobalamin) page, and see B12 nasal spray vs injection for how the forms compare.

2. Iron

Iron is a mineral, not a vitamin, but it belongs on any list about tiredness because it carries oxygen in the blood. Low iron can cause tiredness, weakness, lack of energy and trouble concentrating, and women with heavy periods, pregnant women and frequent blood donors are the most likely to run low (NIH ODS).

Iron can matter even before a standard blood count looks abnormal. In a randomized trial of 198 women aged 18 to 53 with unexplained fatigue, low ferritin (under 50 µg/L) and normal hemoglobin, 80 mg of iron a day for 12 weeks lowered fatigue scores by 47.7%, against 28.8% on placebo (Vaucher et al., 2012). Iron can be harmful in excess, so take it only if a test shows you need it.

3. Vitamin D

Your skin makes vitamin D in sunlight, so people who get little sun, older adults and people with darker skin are more likely to be low (NIH ODS). In a double-blind trial of 120 otherwise healthy adults (average age 29) with fatigue and low vitamin D, fatigue scores fell more with vitamin D3 than with placebo, and 72% against 50% reported feeling less tired; the more their vitamin D level rose, the more fatigue improved (Nowak et al., 2016). The adult upper limit is 4,000 IU (100 mcg) a day. See our vitamin D3 page for more.

4. Magnesium

Magnesium helps muscles and nerves work and plays a part in making energy in cells (Tardy et al., 2020). Low magnesium can cause loss of appetite, nausea, fatigue and weakness, and older adults are among those most likely to get too little (NIH ODS). Food comes first: leafy greens, nuts, seeds, beans and whole grains. If you supplement, the upper limit from supplements is 350 mg a day for adults, and more can cause diarrhea and cramping. Our guide to magnesium malate for sleep, energy and recovery covers one popular form.

5. The Other B Vitamins

Thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), B6, biotin and folate all help turn food into energy (Tardy et al., 2020). A varied diet covers most people, and a B complex is a simple option if your diet is limited. Our vitamin B6 (P5P) page explains the active form of B6.

Vitamins for Energy for Women

Iron is the first thing to check for tired women who still have periods, because the daily need (18 mg from age 19 to 50) is more than twice a man's, and heavy periods raise the risk of running low. The iron trial above enrolled only women, and the authors suggested considering iron for women with unexplained fatigue and ferritin under 50 µg/L (Vaucher et al., 2012). Vitamin B12 and vitamin D are the next two to check, especially if you eat little animal food or spend most of the day indoors. From age 51, the daily iron need for women drops to 8 mg.

Vitamins for Energy for Men

Men need far less iron (8 mg a day) and are less likely to run low, so they should not take iron unless a test shows they need it. For tired men, vitamin D and vitamin B12 are the more useful checks, and B12 matters more with age, a plant-based diet, or long-term use of metformin or acid reducers. Magnesium intake from food is often low in men over 70 (NIH ODS).

If you would rather get more B12 from food first, our chart of vitamin B12 foods lists the amount in fish, meat, dairy, eggs and fortified foods.

Choosing between a single B12 product and a full set of B vitamins? Our guide to B complex vs B12 compares them.

Food is the first place to get these nutrients; our guide to foods that give you energy lists the best sources.

How to Choose a Vitamin for Energy

• Get tested first: ask your doctor about B12, ferritin (iron stores), vitamin D and a blood count if you have been tired for weeks.
• Match the dose to the need: correct a shortfall, then stay near the daily amounts above. Keep vitamin D under 4,000 IU and supplemental magnesium under 350 mg a day unless your doctor advises otherwise.
• Check the form: methylcobalamin is an active form of B12, and vitamin D3 (cholecalciferol) is the form made in skin.
• Read the label for stimulants: many "energy" products get their kick from caffeine, not vitamins. Our guide to supplements for energy without the crash covers stimulant-free options.
• Look for third-party tested ingredients and a clear amount for each nutrient.

Daily habits matter as much as nutrients; our morning routine checklist covers daylight, water, movement and caffeine timing.

Other Common Causes of Tiredness

A vitamin will not make up for short sleep, stress, skipped meals, dehydration or long days without moving. If those are in the picture, fix them first. Our guides on fatigue vs burnout and brain fog causes walk through the everyday culprits, and NAD+ and cellular energy explains how cells make energy in the first place. For more, visit our non-stimulant energy and focus guide.

Mild dehydration is another common reason for feeling tired; our guide to electrolytes explains the signs and the foods that help.

Our Products for Energy

• Methyl B-12 Nasal Spray: 408 mcg of vitamin B12 as methylcobalamin per two-spray serving, once a day.
• NAD+ Nasal Spray: NAD+ and alkaline water, in three strengths (35, 100 or 170 mg per two-spray serving).
• Clarity Nasal Spray: NAD+, alpha GPC, huperzine A and methyl B12, for focus and mental clarity.

Our Vitamin D3 + K2 Drops are coming soon.

If you are choosing a B12 supplement, our guide to methylcobalamin vs cyanocobalamin explains how the forms differ.

When to See a Doctor

Safety note: see a doctor if you have been tired for more than a few weeks, if tiredness keeps getting worse, or if it comes with shortness of breath, a racing heart, unplanned weight change, very heavy periods, numbness or tingling, low mood or snoring with daytime sleepiness. A doctor can check for anemia, thyroid problems and low B12, iron or vitamin D, and review your medicines. Keep iron supplements away from children, since an accidental overdose is dangerous. Ask your doctor before taking vitamin D if you take statins, steroids or thiazide diuretics. For the daily habits that matter alongside vitamins, see our guide on how to get more energy.

Sources

• NIH Office of Dietary Supplements. Vitamin B12: Fact Sheet for Consumers. Updated 2023. ODS
• Vaucher P et al. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. CMAJ, 2012. PubMed
• Nowak A et al. Effect of vitamin D3 on self-perceived fatigue: A double-blind randomized placebo-controlled trial. Medicine, 2016. PubMed
• Tardy AL et al. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. Nutrients, 2020. PubMed
• NIH Office of Dietary Supplements. Iron: Fact Sheet for Consumers. Updated 2023. ODS
• NIH Office of Dietary Supplements. Vitamin D: Fact Sheet for Consumers. Updated 2022. ODS
• NIH Office of Dietary Supplements. Magnesium: Fact Sheet for Consumers. Updated 2021. ODS

Frequently Asked Questions

What vitamins are good for energy?

Vitamin B12, iron, vitamin D and magnesium are the most linked to tiredness, along with the other B vitamins. They help most when your level is low, so a blood test is the best place to start.

Which B vitamin is best for energy?

Vitamin B12 is the one most often low, especially in people who eat little animal food, older adults and people taking metformin or acid reducers. All the B vitamins help turn food into energy, so a varied diet or a B complex covers the rest.

What vitamins should I take for energy and tiredness as a woman?

Check iron first if you still have periods, then vitamin B12 and vitamin D. In a trial of tired women with low iron stores, iron lowered fatigue scores more than placebo.

What vitamins should men take for energy?

Vitamin D and vitamin B12 are the most useful to check. Men need less iron and should not take it unless a test shows they are low.

Can vitamins give you energy right away?

No. Vitamins are not stimulants. If you are low, energy tends to improve over weeks as your level recovers; the iron trial measured results at 12 weeks.

Can low vitamin D make you tired?

It can. In a placebo-controlled trial of tired adults with low vitamin D, more people felt less tired after vitamin D3 than after placebo.

Is it safe to take energy vitamins every day?

At the daily amounts in this guide, usually yes. Stay under the upper limits for vitamin D and supplemental magnesium, take iron only if you need it, and check with your doctor if you take medicines.

How do I know if I am low in a vitamin?

A blood test is the only reliable way. Ask about B12, ferritin, vitamin D and a full blood count if you have been tired for several weeks.

These statements have not been evaluated by the Food and Drug Administration. This content is for education and is not medical advice. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk with a healthcare provider before starting a new supplement if you are pregnant, breastfeeding or taking medication.