Vitamins B2, B3, B5 and B6, vitamin C and magnesium are the nutrients with backing to help reduce tiredness and fatigue, that feeling of physical and mental exhaustion that drains energy from the day. They work best on the basis of a varied diet; a supplement only makes sense when your usual intake falls short or demand increases.
Which vitamins and minerals help reduce tiredness and fatigue?
Energy metabolism —the set of reactions that transform the nutrients in food into the energy your cells use— depends on several vitamins and minerals working as a team. When the intake of these micronutrients is not adequate, signs of physical and mental fatigue can appear, because they take part in energy production, oxygen transport and the workings of the nervous system. A reference review analysed eight B-group vitamins (B1, B2, B3, B5, B6, B8, B9 and B12) together with vitamin C, iron, magnesium and zinc for their role in energy and fatigue. You can explore more content on this topic in our energy section.
B-group vitamins: the engine of energy metabolism
The B-group vitamins are the leading players in this mechanism. Riboflavin (B2), niacin (B3), vitamin B6 and pantothenic acid (B5) contribute to the reduction of tiredness and fatigue. In addition, B6, B12, niacin, riboflavin and biotin contribute to normal energy-yielding metabolism, and biotin also takes part in the normal functioning of the nervous system. Each one plays a specific role: pantothenic acid, for example, is involved in the synthesis of coenzyme A, a key molecule for extracting energy from food. If you want to go deeper vitamin by vitamin, see the entry on pantothenic acid (vitamin B5).
Seen one by one, each B vitamin adds its own nuance: thiamine (B1) and riboflavin (B2) help release energy from carbohydrates; niacin (B3) takes part in hundreds of reactions of cellular metabolism; vitamin B6 is involved in making use of proteins; and folate (B9) together with vitamin B12 take part in the normal formation of blood cells, including the red blood cells that carry oxygen to the tissues.
Vitamin C, magnesium and iron: energy, nervous system and oxygen
Beyond the B group, three other nutrients complete the picture. Vitamin C contributes to the reduction of tiredness and fatigue and to normal energy-yielding metabolism; magnesium contributes to the normal functioning of the nervous system and also to the reduction of tiredness and fatigue; and iron, like vitamin B12, contributes to the reduction of tiredness and fatigue, largely because of its role in oxygen transport. You will find more detail in the entry on vitamin C.
Iron deserves a caveat. Research with iron has focused on menstruating women with low iron stores (assessed by ferritin, the protein that reflects stored iron) but without anaemia: in that specific profile, several trials have documented effects on the sensation of fatigue. In a study of 198 women with ferritin below 50 µg/L, fatigue was reduced by 47.7% with iron versus 28.8% with placebo at 12 weeks. In another, smaller trial of just 20 non-anaemic women with ferritin below 20 µg/L, iron was also associated with lower muscle fatigability (how quickly a muscle loses strength under exertion). These are promising findings, but limited to a specific profile: they do not mean that iron "gives energy" to just anyone.
In the case of vitamin C, a trial with 141 workers observed lower fatigue scores versus placebo; it is worth clarifying that the vitamin was given intravenously, not orally, so its conclusions do not transfer directly to a supplement taken by mouth.
What each nutrient brings against tiredness
Functions recognised by the European nutrition and health claims rules.
| Nutrient | Reduces tiredness and fatigue | Normal energy metabolism | Functioning of the nervous system |
|---|---|---|---|
| Riboflavin (B2) | |||
| Niacin (B3) | |||
| Pantothenic acid (B5) | |||
| Vitamin B6 | |||
| Vitamin B12 | |||
| Vitamin C | |||
| Magnesium | |||
| Biotin |
Which foods contain these vitamins for energy?
Before thinking about a supplement, the foundation is the plate. These nutrients are present in everyday foods:
- Pulses and whole grains: provide B-group vitamins and magnesium.
- Lean meats, fish, eggs and shellfish: sources of B12, B6 and well-available iron.
- Green leafy vegetables and nuts: rich in magnesium, folate (B9) and plant-source iron.
- Citrus fruits, kiwi, peppers and strawberries: stand out for their vitamin C, which also improves the absorption of plant-source iron.
A varied diet covers the needs of most people. A supplement comes into play only when, for whatever reason, that intake falls short.
Tiredness from a deficiency of iron, vitamin B12 or folate
When tiredness becomes persistent and does not improve with rest, sometimes there is a micronutrient deficiency behind it that only a blood test can confirm. The most common ones have to do with oxygen transport: iron is part of haemoglobin —the protein in red blood cells that distributes oxygen throughout the body—, while vitamin B12 and folate are needed for the body to make those red blood cells normally. An insufficient, sustained intake of any of the three can show up as a lack of energy.
Vitamin B12 is found mainly in foods of animal origin —meat, fish, eggs and dairy—, so people on strict vegetarian or vegan diets are the ones who gain most from keeping an eye on their intake, whether through fortified foods or a supplement. Folate, on the other hand, is abundant in green leafy vegetables, pulses and citrus fruits. Faced with tiredness that does not ease, it is sensible to consult a healthcare professional and, if appropriate, check these levels before supplementing blindly.
When does it make sense to take a supplement for physical and mental tiredness?
A supplement is no substitute for a balanced diet, but it can make sense in specific situations: restrictive or poorly varied diets, periods of greater physical or mental demand, or stretches of insufficient rest in which the body feels the lack of resources. In those contexts, magnesium is especially interesting for its contribution to the normal functioning of the nervous system, which is involved in cycles of activity and rest. If this route interests you, you can compare the different forms of magnesium and see which fits best depending on the time of day.
Research offers some support. In a 16-week trial, 138 healthy young adults (aged 20 to 50) who took a multivitamin rich in B-group vitamins daily recorded lower physical-fatigue scores than placebo in that study. It is an encouraging result, although it is worth reading with caution: it is a single study and a specific formula.
Among the options formulated with this approach, PLENIAGE ENERGY PRO combines alpha-lipoic acid, magnesium and eight vitamins (B2, B3, B5, B6, C, E and biotin); of these, B2, B3, B5, B6 and magnesium contribute to the reduction of tiredness and fatigue, while biotin and vitamin C contribute to normal energy-yielding metabolism. You can see the rest of the formulas in the energy and performance collection.
Frequently asked questions
Which vitamins are good for tiredness and sleep?
Magnesium is the most relevant nutrient on this point: it contributes to the normal functioning of the nervous system, which is involved in cycles of activity and rest. Even so, no nutrient replaces good sleep habits: regular schedules, fewer screens before bed and a calm environment remain the foundation.
Does a B-complex really help with tiredness?
Yes, within limits. Several B-group vitamins —B2, B3, B6 and B5— contribute to the reduction of tiredness and fatigue, and others (B6, B12, B2, B3 and biotin) to normal energy-yielding metabolism. In a 16-week trial, a multivitamin rich in these vitamins was associated with less physical fatigue than placebo. The benefit is greater when you started from an insufficient intake; it is not an immediate stimulant.
Is a lack of energy always due to a lack of vitamins?
No. A lack of energy has many causes: insufficient sleep, dehydration, sustained stress, little physical activity or a disorganised diet. A vitamin or mineral deficiency is only one of the possible explanations, and not always the main one. If the tiredness is intense or prolonged, the sensible thing is to discuss it with a healthcare professional before supplementing blindly.
How long does it take to notice a supplement for tiredness?
Do not expect changes overnight. The studies that observed effects on fatigue worked with windows of between 12 and 16 weeks of continued use. Consistency, together with rest and nutrition, counts for more than speed.
Which B-group vitamins help most with tiredness?
Riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6 and vitamin B12 contribute to the reduction of tiredness and fatigue. There is no need to take them separately: in the diet and in multivitamin complexes they go together and work as a team.
Can tiredness be due to a lack of iron or vitamin B12?
Yes. Iron, vitamin B12 and folate take part in oxygen transport and in the formation of red blood cells, so a sustained deficiency can show up as a lack of energy. Only a blood test can confirm it: faced with tiredness that does not ease, consult a healthcare professional before supplementing.
If you want an overview of energy and vitality, you may be interested in our energy and performance guide.
- Tardy AL, et al. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. Nutrients. 2020. PMID: 31963141.
- Pipingas A, et al. The effects of multivitamin supplementation on mood and general well-being in healthy young adults. A laboratory and at-home mobile phone assessment. Appetite. 2013. PMID: 23727255.
- Vaucher P, et al. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. CMAJ. 2012. PMID: 22777991.
- Brutsaert TD, et al. Iron supplementation improves progressive fatigue resistance during dynamic knee extensor exercise in iron-depleted, nonanemic women. Am J Clin Nutr. 2003. PMID: 12540406.
- Suh SY, et al. Intravenous vitamin C administration reduces fatigue in office workers: a double-blind randomized controlled trial. Nutr J. 2012. PMID: 22264303.