Spinach: Nutrition, Benefits and Raw vs Cooked Spinach

Spinach is one of the most nutrient-dense vegetables in the USDA database: one raw cup has only about 7 calories yet more than a full day’s Daily Value for vitamin K, plus folate, vitamin A and manganese. Cooked spinach shrinks dramatically, so a cup of it delivers far more of everything. This guide covers spinach nutrition from USDA numbers, what the evidence does and does not say about spinach benefits, raw vs cooked spinach, the truth about spinach and iron (including the famous decimal point story), and the oxalate, vitamin K and food safety points worth knowing.

Peptide Labs does not sell spinach or spinach products. This article is general nutrition information, not medical advice.

Spinach nutrition facts (USDA)

The table uses USDA FoodData Central (SR Legacy) values, with percent Daily Value (%DV) based on the FDA Daily Values used on food labels. FDC IDs: raw 168462, boiled without salt 168463, frozen and boiled without salt 169288. Serving sizes are the USDA portions for each entry, so they differ.

Canned spinach is similar in vitamins, but regular canned spinach (FDC 169286, drained) lists 689 milligrams of sodium per cup in USDA data, 30% of the Daily Value, so no-salt-added cans or a rinse make a difference if you watch sodium. Spinach is also one of the richest sources of the carotenoids lutein and zeaxanthin in USDA data, about 12,200 micrograms per 100 grams raw; our lutein guide explains what those pigments are. For other foods rich in the minerals above, see magnesium foods and calcium foods; for folate forms, see methylfolate.

Raw vs cooked spinach: which is better for you?

Neither form wins on every measure. Raw vs cooked spinach differs in two ways: what heat does to individual nutrients, and how much spinach ends up in a serving. Per 100 grams, USDA lists raw spinach at 28.1 milligrams of vitamin C and boiled spinach at 9.8, and folate falls from 194 to 146 micrograms DFE, because both nutrients are sensitive to heat and leach into cooking water. Other USDA values per 100 grams are higher in the boiled entry, such as iron (2.71 versus 3.57 milligrams) and calcium (99 versus 136), mostly because the leaves lose water and become more concentrated.

Serving size matters even more. A cup of raw leaves weighs about 30 grams, while a cup of cooked spinach weighs about 180 grams, so a cooked cup contains roughly six times as much spinach. That is why the cooked column in the table looks so much richer. A practical approach is to eat both: raw leaves in salads and sandwiches for vitamin C and folate, and cooked spinach when you want a larger amount of greens in one sitting.

Spinach benefits: what the evidence supports

The clearest spinach benefits are nutritional: few calories, a lot of vitamin K, vitamin A, folate and manganese, and useful magnesium and fiber once cooked. Research on spinach compounds such as lutein and nitrate is ongoing, but most claims you will see online go well beyond what human trials show, so read bold promises with caution. What can be said with confidence is that spinach is an easy way to add vegetables to many dishes, from eggs and soups to pasta and smoothies.

Spinach and iron: nonheme iron and vitamin C

Spinach does contain iron, but it is nonheme iron, the plant form. The ODS iron fact sheet notes that vitamin C enhances the absorption of nonheme iron, and that meat, poultry and seafood eaten in the same meal also help. Iron is absorbed less efficiently from vegetarian diets (about 5% to 12%) than from mixed diets that include meat, seafood and vitamin C (about 14% to 18%), according to the ODS. Pairing spinach with citrus, tomatoes or peppers is an easy habit. Our list of iron sources compares plant and animal foods.

The decimal point story

You may have read that spinach became famous for iron because a scientist misplaced a decimal point and overstated its iron tenfold. A peer-reviewed 2014 paper in Social Studies of Science by Ole Bjorn Rekdal used that tale as a case study of an academic urban legend. Following the trail of citations, he concluded the decimal point error was undocumented and most likely never happened; the doctor who spread the story in 1981 later admitted he could not remember where he had read it. The myth about the myth, in other words, is the shaky part, while the plain USDA numbers above are what matter.

Calcium and oxalate

Spinach is high in oxalic acid, which binds calcium. The ODS calcium fact sheet reports that the body absorbs only about 5% of the calcium in spinach, compared with about 27% from milk, so spinach is not a reliable calcium source despite the number on paper. Oxalate also matters for people prone to calcium oxalate kidney stones: the National Kidney Foundation lists spinach among very high oxalate foods, and a 2019 review lists it among foods stone formers are often told to avoid. If you have had kidney stones, ask your clinician or a dietitian how spinach fits your plan; our guide to oxalates explains the background.

Who should be careful with spinach

• People taking warfarin: the ODS and MedlinePlus advise keeping vitamin K intake consistent rather than making sudden changes. Spinach is one of the richest vitamin K sources, so talk with your prescriber; see our vitamin K guide.
• People with a history of kidney stones: discuss oxalate with your clinician before making spinach a daily staple.
• Parents of young babies: an American Academy of Pediatrics clinical report notes that nitrate poisoning from home-prepared vegetable foods for infants continues to be reported, while commercially prepared baby foods carry little or no risk. Ask your pediatrician before making homemade vegetable purees.
• Anyone using a lot of canned spinach: check the sodium on the label.

Spinach food safety: the 2006 E. coli outbreak

Like other raw greens, spinach can occasionally carry harmful bacteria. In 2006, a multistate outbreak of E. coli O157:H7 was traced to bagged fresh spinach. A report by CDC and state investigators in Emerging Infectious Diseases found that eating bagged spinach was significantly linked to illness, the outbreak strain was found in bags of one brand, and 205 people nationally were ill with that strain. A Wisconsin investigation published in Clinical Infectious Diseases described how fast laboratory matching led to a prompt voluntary recall. Outbreaks like this are rare, but they are why recalls matter; check recall notices and discard recalled products. Cooking spinach thoroughly kills bacteria, which is one more reason to enjoy it both ways.

How to choose, store and use spinach

• Look for crisp, deep green leaves without slimy or yellow patches.
• Store dry in the refrigerator, loosely wrapped; use within a few days.
• Baby spinach is tender for salads; mature flat or curly leaves hold up better to cooking.
• A big pile of raw leaves wilts down to a small amount, so start with more than you think you need.
• Frozen spinach is already wilted; squeeze out the water before adding it to dips, eggs or fillings.
• Compare greens in our guides to leafy green vegetables, kale, Swiss chard, arugula and Brussels sprouts.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Brussels Sprouts: USDA Nutrition and Are They Healthy?, Leafy Greens: USDA List of Dark Greens, Spinach vs Kale and Tips, Oxalates: High Oxalate Foods, Low Oxalate Foods and Kidney Stones.