Vitamins in bananas: nutritional values per piece and what they provide
September 25, 2026about 15 minutesby mybody®x Editorial & Expert Team
Key takeaways
A medium banana weighing 118 g provides around 0.43 mg of vitamin B6 and around 422 mg of potassium, calculated from data from the US Department of Agriculture (USDA, 2019). For vitamin B6, that’s around 27 to 31 percent of the daily intake set by the German Nutrition Society (DGE, 2019). Bananas provide very little vitamin K.
Bananas contribute most in terms of vitamin B6. They provide around one-tenth each of the estimated value for potassium (DGE estimate, 2016) and the guideline value for fiber (DGE, 2021), based on USDA data.
Bananas are not a source of vitamin K: one fruit provides around 1 percent of the DGE estimate (derived from 2000), calculated using USDA data (2019).
All percentages are our own calculations based on US database values for a banana with no variety or ripeness specified.
In this article
What are the nutritional values of a banana per 100 g and per piece?
Per 100 grams, a raw banana has 89 kcal and 22.8 g of carbohydrates, including 12.2 g of sugar, according to the US nutrient database FoodData Central (USDA, 2019). Based on our own calculation, a medium banana weighing 118 g contains around 105 kcal.
Per medium banana (118 g), calculated
around 105 kcal
Energy, at 89 kcal per 100 g
about 422 mg
Potassium, at 358 mg per 100 g
about 0.43 mg
Vitamin B6, at 0.367 mg per 100 g
around 3.1 g
Fiber, at 2.6 g per 100 g
Source: U.S. Department of Agriculture, FoodData Central (SR Legacy), 2019 · Values per piece calculated based on 118 g
The figures in this article come from FoodData Central, the U.S. Department of Agriculture’s nutrient database, dataset SR Legacy, published in April 2019. We use it because it provides values per 100 g of edible portion as well as serving weights. A medium banana weighs 118 g in the database. The range is from 101 g for a small banana to 136 g for a large one.
Per 100 g, bananas provide 1.09 g of protein and 0.33 g of fat (USDA, 2019). Carbohydrates make up the largest share, at 22.8 g. For a medium banana, that comes to around 26.9 g of carbohydrates, including around 14.4 g of sugar and around 6.4 g of starch. Fiber amounts to 2.6 g per 100 g, or around 3.1 g per fruit.
What the database doesn’t tell us is which variety was measured or how ripe the fruit was. The dataset is simply called “Bananas, raw.” For the question of which vitamins they contain, that’s a good starting point. Where the information has its limits, we explain further down in the chapter on the accuracy of the values.
Why calculate the figures per fruit at all? Because nobody eats 100 g of banana. A fruit is the unit you think in when you put one in your bag in the morning. That’s why this article gives both figures side by side: the database value per 100 g and the calculation for 118 g.
What vitamins and minerals are in a banana?
Bananas provide the largest share of vitamin B6: a medium fruit covers around 27 percent of the reference value for men and around 31 percent for women, based on USDA data (2019) and DGE reference values (2019).
“But bananas are full of vitamins.” That’s clearly true of one vitamin, but only to a limited extent for the others. To show this, we compare the database values with those of the German Nutrition Society (DGE). Reference value is the umbrella term for the daily intake amount that the DGE derives for each nutrient. It provides this as a recommendation, an estimated value, or a guideline value.
An estimated value is not strictly speaking a recommendation, but a value for an adequate intake. A guideline value is a point of reference, such as the one the DGE gives for fiber. All percentages in this chapter are our own calculations, based on USDA data and the DGE reference values.
How much vitamin B6 does a banana have?
A medium banana provides around 0.43 mg of vitamin B6, calculated for 118 g from 0.367 mg per 100 g (USDA, 2019). The DGE gives reference values of 1.6 mg per day for men and 1.4 mg for women (2019 derivation). That works out to around 27 percent for men and around 31 percent for women. Per 100 g, the figures are around 23 and 26 percent, respectively.
How much vitamin C does a banana have?
At 8.7 mg per 100 g, a medium banana contains around 10.3 mg of vitamin C (USDA, 2019, calculated). The DGE recommends 110 mg per day for men and 95 mg for women, and 155 mg and 135 mg for smokers, respectively (2015 derivation). A banana therefore provides around 9 percent of the value for men and around 11 percent for women. In its list of examples of sources of vitamin C, the DGE mentions peppers and citrus fruits, among others; bananas are not included.
How much folate is in a banana?
A medium-sized banana contains about 23.6 µg of folate, calculated from 20 µg per 100 g (USDA, 2019). The database lists the value in folate equivalents, the common unit used to calculate the different forms of the vitamin. According to the D-A-CH reference values, the shared values for German-speaking countries, as reported by the Federal Institute for Risk Assessment (BfR, 2024), the recommendation for adults is 300 µg of folate equivalents per day. The banana provides about 8 percent of that amount. Equating the US unit with German folate equivalents is an approximation.
How much potassium does a banana contain?
At 358 mg per 100 g, a medium-sized banana contains about 422 mg of potassium (calculated using USDA, 2019). The DGE's estimated value for adults is 4,000 mg per day (derivation 2016). One banana provides about 11 percent of that amount. That's a solid contribution, but not an exceptional amount, as the chapter on claims shows.
How much magnesium does a banana contain?
A medium-sized banana contains about 31.9 mg of magnesium, based on 27 mg per 100 g (calculated using USDA, 2019). For adults aged 19 and over, the DGE's estimated values are 350 mg for men and 300 mg for women (derivation 2021). That works out to about 9 and 11 percent, respectively. “Magnesium deficiency is relatively rare in people with healthy metabolisms who eat a balanced diet,” the DGE writes in its questions and answers on magnesium (2025).
For dietary fiber, the DGE recommends at least 30 g per day for women and men alike (derivation 2021). A medium-sized banana contains about 3.1 g (calculated using USDA, 2019), covering about 10 percent of that amount. Vitamin K is intentionally omitted from this list: because of the search queries about it, it gets its own chapter.
Per medium-sized banana (118 g) · amounts calculated using USDA data (2019) and DGE reference values (derivations from 2000 to 2021); folate according to D-A-CH, as reported by the BfR (2024)
| Nutrient | Per banana | Amount |
|---|---|---|
| Vitamin B6 | about 0.43 mg | about 27% (men, 1.6 mg) · about 31% (women, 1.4 mg) |
| Vitamin C | about 10.3 mg | about 9% (men, 110 mg) · about 11% (women, 95 mg) |
| Folate | about 23.6 µg folate equivalents | about 8% of 300 µg (D-A-CH, as reported by the BfR) |
| Vitamin K (phylloquinone, the plant-based vitamin K1) | about 0.6 µg | about 1% of the estimated value of 60 to 80 µg |
| Potassium | about 422 mg | about 11% of the estimated value of 4,000 mg |
| Magnesium | about 31.9 mg | about 9% (men, estimated value 350 mg) · about 11% (women, estimated value 300 mg) |
| Fiber | around 3.1 g | around 10% of the recommended minimum of 30 g |
What a banana provides - and what it doesn’t
A medium-sized banana provides around 27 to 31 percent of the DGE reference value for vitamin B6, calculated using USDA data (2019) and DGE (2019). For potassium (estimated value, DGE 2016) and fiber (recommended value, DGE 2021), it provides around one-tenth; for vitamin C (DGE 2015) and magnesium (estimated value, DGE 2021), around 9 to 11 percent, depending on sex. Folate provides around 8 percent of the D-A-CH recommendation (as reproduced by the BfR, 2024), and vitamin K around 1 percent of the DGE estimated value (derived 2000). A banana alone does not meet the reference value for any of these nutrients.
How much vitamin K is in a banana?
Very little: The database lists 0.5 µg per 100 g, while a medium-sized banana contains around 0.6 µg (calculated from USDA, 2019). By comparison, broccoli provides 102 µg per 100 g.
The database value refers to phylloquinone. This is the name for plant-based vitamin K1, which the DGE counts among the best-known vitamin K compounds. Anyone searching for “banana vitamin K” wants to know whether the fruit provides a significant amount. The figures give a clear answer.
The DGE gives estimated values for vitamin K intake: 70 µg per day for men and 60 µg for women aged 19 to under 51, rising to 80 µg and 65 µg respectively from age 51 onward (derived 2000). Compared with these 60 to 80 µg, the banana’s approximately 0.6 µg is negligible. One fruit provides around 1 percent, calculated using USDA data and DGE reference values.
Cited source
“Good sources of vitamin K are above all green vegetables (e.g. spinach, some types of lettuce and cabbage), milk and dairy products, meat and eggs.”
German Nutrition Society
Reference values for nutrient intake, vitamin K (derived 2000)
Fruit doesn’t appear on this list. That’s the honest answer when looking for vitamin K in bananas: bananas are not a source of vitamin K. If you’re looking at your intake over the course of a day, significant amounts come from green vegetables, not the fruit bowl.
Anyone who needs to monitor their vitamin K intake because of a medication should discuss dietary questions with their family doctor. This article provides nutritional values; it does not replace that conversation.
Which claims about banana vitamins hold up?
Two claims are only partly true: Bananas provide potassium, but less per 100 g than cod, and green and ripe bananas differ in their ratio of starch to sugar.
“The figures contradict each other everywhere.” That’s a valid objection. Nutritional values are measurements of actual fruit, and they vary. The DGE notes that vitamin C levels in foods can fluctuate, among other things, due to harvest timing and storage (inferred from 2015). So it’s particularly worth checking the source for the following two claims.
Claim and evidence
Claim
“Bananas are potassium bombs.”
What the source shows · how certain it is
Cod contains 413 mg of potassium per 100 g, compared with 358 mg for a banana (USDA, 2019). A medium banana provides about 11 percent of the DGE estimate of 4,000 mg (calculated). The DGE notes: “Potassium deficiency resulting from a low dietary potassium intake is rare.” (DGE, 2016) In short: a solid contribution, not an exceptional amount. The evidence is reliable.
Claim
“Green and ripe bananas have the same nutritional values.”
What the source shows · how certain it is
Not quite. In unripe bananas, starch makes up 80 to 90 percent of carbohydrates, and as they ripen, it turns into free sugars (Hermansen et al., 1992). Ercan et al. (1993) also report that as ripeness increases, the starch content falls and the sugar content rises. In short: The shift from starch to sugar is documented, but neither study provides vitamin values.
What does this mean for the figures in the database? The 5.38 g of starch and 12.2 g of sugar per 100 g apply to a banana with no ripeness specified (USDA, 2019). A greener fruit is likely to contain more starch, and a riper one more sugar, but the database doesn’t show how large the difference is in a given case.
Small studies have produced inconsistent findings on whether ripeness affects blood sugar, and they aren’t enough to draw conclusions about you.
How do a banana’s vitamins fit into everyday life?
As one component among several foods eaten throughout the day: A medium banana provides about 105 kcal and about 3.1 g of fiber (calculated from USDA, 2019).
The nutritional values answer the question of what a banana contains. How many to eat per day is another question, and it has its own guide: Bananas per day: how many are healthy. Find out what banana fiber does in the guide to bananas and fiber.
We deliberately separate whether bananas help or hinder weight loss from their nutritional value. That’s where we discuss ripe or green, in the evening or cooked; here, we focus on what the fruit contains. You’ll find the answer about weight in the article Bananas and weight loss: good or bad?
In everyday life, it’s worth looking at the combination. Bananas provide very little calcium, just 5 mg per 100 g. Low-fat kefir in the US database contains 130 mg of calcium per 100 g (USDA, 2019). Oats contain 10.1 g of fiber per 100 g, while bananas contain 2.6 g. So combining a banana with other foods changes the nutritional balance of breakfast without requiring any one ingredient to do all the work.
Key takeaway
Bananas mainly provide vitamin B6; they are not a source of vitamin K.
The calculations in this article refer to a raw fruit. The database lists the banana as “raw,” meaning uncooked. The sources used in this article do not provide values for cooked or dried bananas, so we don’t list any for those.
How much vitamin B6 and potassium do you personally need?
Reference values don’t tell you this: DGE values are considered averages for groups, divided by age and sex, not measures for an individual person.
The percentages in this article refer to these average values. When a banana provides around 31 percent of the reference value for vitamin B6 for women (calculated using USDA, 2019, and DGE, 2019), this refers to a value that applies to the group of adult women. No nutrition table shows your individual needs.
This is where an offer from mybody®x (MYBODY Lab GmbH) comes in. The NutriCare INFINITY DNA test analyzes selected SNPs, or individual heritable sections of your DNA, from a saliva sample. The test description states: “Your vitamin and mineral needs – where they are above average and what you can pay attention to in everyday life.”
The analyses include vitamin B6, evaluated at the ALPL gene, and potassium, evaluated at the WNK1 gene. A gene is a section of genetic information. These are the two nutrients to which bananas make their greatest contribution. The result describes a predisposition, not a prediction. Predisposition is one factor among several, and it is not a certainty.
The evidence base is also important context. A DGE position paper noted in 2022 that evidence for the success of gene-based dietary recommendations was still largely lacking (paraphrased from Holzapfel et al., 2022). The test therefore offers insights for your diet, not proof that this knowledge will help you make it better.
The test description explicitly states what it does not do: “It doesn't tell you what to do. There is no diet plan and no restrictions. It is not a diagnostic procedure and does not replace medical advice.”
From the mybody®x range · DNA test
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How accurate is the nutritional information for bananas?
As accurate as its source: The values come from a U.S. database and describe a raw banana with no variety or ripeness specified (USDA, 2019).
First, origin. FoodData Central is a database maintained by the U.S. Department of Agriculture, not a measurement of produce sold in Germany. The serving weights are U.S. sizes, measured in inches. A banana from your local supermarket may weigh more or less than the 118 g used in our calculations.
Second, ripeness. Studies by Hermansen et al. (1992) and Ercan et al. (1993) show that the ratio of starch to sugar changes as fruit ripens. The German Nutrition Society (DGE) notes that vitamin C content can vary depending on the harvest and storage (conclusion, 2015). A value in a table is therefore an average, not a guarantee for the fruit in your hand.
Third, our own calculations. We calculated all the values per fruit and all the percentages of the reference value ourselves, using USDA data and DGE reference values, and rounded them to the nearest whole number. The folate value is based on the D-A-CH reference values, as reproduced by the BfR (2024). Equating the US unit for folate with the German folate equivalents remains an approximation.
And what about the test? NutriCare INFINITY describes genetic predispositions. Genetic variants indicate probabilities across populations, not certainties for an individual. If you have symptoms or pre-existing conditions, your family doctor’s office is the first place to turn.
Is a banana a good source of vitamins?
For vitamin B6, yes: a medium banana provides around 27 to 31 percent of the reference value, calculated using USDA data (2019) and DGE (2019). But it provides hardly any vitamin K.
If you value bananas as a source of potassium, you’re not wrong, but it’s easy to overestimate their contribution. Around 11 percent of the DGE estimate (calculated using USDA, 2019, and DGE, 2016) is a solid contribution, and cod contains more per 100 g.
This idea may be new: the percentages apply to an average person. No table can tell you whether your vitamin B6 or potassium needs are higher. Talking to your doctor or analyzing your genetic predisposition may offer some clues.
“But bananas are packed with vitamins,” we said at the start. They’re not packed with vitamins. They provide one main nutrient.
Frequently asked questions
How many calories are in a banana?
A medium banana weighing 118 g has around 105 kcal, calculated from 89 kcal per 100 g (USDA, 2019). The US database lists a small banana as weighing 101 g and a large one 136 g, so the calorie content varies accordingly. The calculation is for the edible portion, without the peel. If you weigh your banana, you can calculate it yourself using 89 kcal per 100 g.
How much sugar is in a banana?
A raw banana contains 12.2 g of sugar per 100 g, and a medium fruit has around 14.4 g (USDA, 2019, calculated). It also contains around 6.4 g of starch per fruit. The ratio depends on ripeness: as a banana ripens, its starch content decreases and its sugar content increases (Ercan et al., 1993). The database doesn’t specify the ripeness of the bananas used for its values.
Does a banana fill you up?
The DGE lists the effect on satiety as one of the properties of dietary fiber (Reference Values for Dietary Fiber, derivation 2021). A medium banana provides around 3.1 g of fiber, about 10 percent of the guideline value of at least 30 g per day (calculated using USDA data, 2019). The nutritional values alone don’t show exactly how filling a banana is for you.
Does a banana meet your folate needs?
No. A medium-sized banana provides around 23.6 µg of folate, which is around 8 percent of the recommendation of 300 µg of dietary folate equivalents per day for adults. The reference value comes from the D-A-CH reference values, as cited by the BfR (2024); the banana value and percentage are the result of our own calculations based on the US database (USDA, 2019). Treating the two units as equivalent is an approximation.
Why do vitamin figures differ between tables?
Because they are measured in different fruits. The DGE notes that the vitamin C content in foods can vary depending, among other things, on harvest time and storage (derivation 2015). Variety and ripeness also play a role, and tables do not always specify them. The values in this article come from the US database FoodData Central (USDA, 2019) and describe a raw banana without these details.
Next step
Assessing your own vitamin needs
NutriCare INFINITY describes your predisposition to vitamin and mineral needs. It doesn't tell you what to do.
About NutriCare INFINITY Bananas per day: the right amount The amount in the guideRead more
Sources
- U.S. Department of Agriculture, Agricultural Research Service: FoodData Central, SR Legacy dataset (as of 2019) – fdc.nal.usda.gov
- German Nutrition Society: Reference values for nutrient intake (derivations from 2000 to 2021) – dge.de
- German Federal Institute for Risk Assessment: Update (2024): Proposed maximum levels for folic acid in foods, including dietary supplements, Opinion 009/2024 (as of 2024) – bfr.bund.de
- Hermansen K et al.: Influence of ripeness of banana on the blood glucose and insulin response in type 2 diabetic subjects, Diabetic Medicine (as of 1992) – europepmc.org
The nutritional values per 100 g and serving weights are based on [1]; all values per piece and all percentages of the reference value are calculations based on [1] and [2]. The reference values for vitamin B6, vitamin C, vitamin K, potassium, magnesium, and fiber, as well as the quotation about sources of vitamin K, are from [2], supplemented by the DGE’s questions and answers on potassium (2016) and magnesium (2025). The folate value is from [3]. Information on ripeness is based on [4] and Ercan et al., Journal of the American College of Nutrition, 1993. The DGE statement on nutrigenetics paraphrases Holzapfel et al., Molecular Nutrition & Food Research, 2022. Product information for NutriCare INFINITY comes from mybody®x product data, as of September 25, 2026. Sources checked in September 2026.
mybody®x Editorial & Expert Team
Nutrition Nutritional values
The mybody®x editorial and expert team reviews nutrition topics based on public databases and the reference values of professional associations. Learn more about the team on the author page.
Published on September 25, 2026 · Last updated on September 25, 2026
The content is for general information and does not replace medical advice, diagnosis, or treatment.
Our products are not intended to diagnose, treat, cure, or prevent diseases.
DNA analysis is intended to provide dietary and lifestyle guidance. It is not a diagnostic procedure, does not predict disease, and does not replace medical examination or advice. Genetic variants describe probabilities in population groups, not determinations for individuals.
The images in this article were created with AI; the people shown are not real.
