Nutrient-Rich Food Finder
Pick a nutrient — iron, fibre, potassium, B12 and eleven more — and see the best food sources ranked, with what affects absorption.
Top foods
Percent of the FDA adult Daily Value per stated serving, USDA-typical figures. Fortified foods vary by brand; cooking method shifts some values. This ranks food sources — it is not supplement or medical advice.
Six of these fifteen nutrients can't be covered by one serving of anything
We went through all 174 food entries here — 98 distinct foods across fifteen nutrients — and asked a simple question of each nutrient: does its single best source get you through the day? For nine of them, comfortably. For the other six, nothing on the list is enough on its own. Only 33 of the 174 entries (19%) deliver a full Daily Value in one serving at all.
| Nutrient | Best single source | Covers | Servings for a full day |
|---|---|---|---|
| Potassium | Beet greens | 27.9% | 3.6 |
| Calcium | Calcium-set tofu | 33.4% | 3.0 |
| Magnesium | Pumpkin seeds | 37.1% | 2.7 |
| Protein | Chicken breast | 52.0% | 1.9 |
| Fiber | Split peas | 58.2% | 1.7 |
| Vitamin D | Rainbow trout | 81.0% | 1.2 |
Push it harder and eat the three best sources of a nutrient in one day: thirteen of the fifteen now clear 100%. Two still don't. Calcium reaches 92% on tofu plus yogurt plus fortified orange juice, and potassium reaches just 69% on beet greens, white beans and a baked potato. Potassium is the hard one on this page at both depths, and it is the clearest case here for spreading intake across a whole diet rather than hunting for one heroic ingredient.
A rule that nearly works, and the two foods that break it
The obvious explanation is that the six shortfalls are the nutrients you need most of by weight, and that is almost right — rank all fifteen Daily Values by mass and five of the six heaviest are shortfalls. But only five. Two exceptions spoil the rule, and both turn out to be worth more than the rule was.
| Exception | Daily Value | Best source | Why it breaks the rule |
|---|---|---|---|
| Omega-3 fats | 1.6 g — fourth heaviest, above calcium's 1.3 g | Flaxseed oil, 456% | An oil is close to pure nutrient, so it escapes the mass problem entirely. No other food group can. |
| Vitamin D | 20 mcg — second lightest of all fifteen | Rainbow trout, 81% | Quantity was never the obstacle. Scarcity is: the three best sources are rainbow trout, sockeye salmon, cod liver oil, and outside oily fish almost no food naturally contains it. |
So the honest version isn't "you need too much of them." It's that a food has to be either concentrated or fortified to carry a whole day of anything — and for vitamin D, almost nothing in nature is.
Where the choice of food matters, and where it doesn't
A separate question: how far ahead is each nutrient's best source? Oysters carry 10.6× the zinc of the runner-up and beef liver 5.8× the vitamin A, so for those the list past the first row is nearly decorative. At the other end four nutrients are effectively ties — magnesium is exact to the decimal, pumpkin seeds and spinach landing on the same number, with protein, fibre and calcium just behind.
All four ties are also on the shortfall list, which looks like a rule until you check the other direction. It only holds one way: every nutrient whose best source leads by more than 1.35× is covered by a single serving, all six of them — but below that, the two groups mix. Vitamin B12 has one of the flattest lists here, clams leading by a factor of 1.19, and the runner-up still carries about 2,900% of a Daily Value. A flat list is not a poor one. Dominance measures a list's shape, not its height.
One food does more work than any other here: spinach is a top source for seven of the fifteen nutrients — the outright leader, with lentils second at five — and it clears 20% of a Daily Value in six of those seven. 41 of the 98 distinct foods appear more than once, and 21 cover at least two nutrients at 20% or better, which is the practical argument for a short shopping list over a long one.
How to use
- Choose the nutrient you are interested in.
- Read the ranked food sources.
- Note the absorption factors where they apply.
- Discuss any suspected deficiency with a clinician.
Frequently asked questions
Why does the source of iron matter?
Because there are two forms and they absorb very differently. Heme iron from animal sources is absorbed far more readily than non-heme iron from plants. Vitamin C substantially improves non-heme absorption, while tea, coffee and calcium taken at the same time reduce it — which is why the pairing matters as much as the amount.
Is more of a nutrient always better?
No, and several can cause harm in excess. Fat-soluble vitamins accumulate rather than being excreted, iron overload is genuinely dangerous, and high-dose supplements have produced worse outcomes than placebo in some large trials. Food sources make excess far harder to reach than supplements do.
Should I take a supplement?
That depends on evidence of a deficiency, which means a blood test rather than a guess. Some groups have well-established needs — vitamin B12 for those eating no animal products, folate in pregnancy, vitamin D in low-sunlight regions. Supplementing on suspicion is common and frequently pointless.
Do cooking and storage affect nutrient content?
Considerably for some. Water-soluble vitamins leach into cooking water and degrade with heat and time, so steaming preserves more than boiling. Others become more available with cooking — the lycopene in tomatoes is a well-known example. There is no single rule.
Are the amounts in these foods reliable?
Approximate. Nutrient content varies with variety, soil, season, ripeness and storage, sometimes substantially. Published tables give typical values, and treating them as exact for a specific item on your plate is expecting more precision than exists.
Can I diagnose a deficiency from symptoms?
Not reliably — the symptoms of most deficiencies are vague and overlap with a great many other things, including simply being tired. Fatigue is not a diagnosis. A blood test and a clinician are what settle it, and nothing here is medical advice.
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