How Much Calcium Is In A Cup Of Broccoli? | The Absorption

When people reach for broccoli, they usually have fiber or vitamin C in mind. Calcium rarely gets the spotlight — partly because dairy dominates that conversation, and partly because the green florets don’t look like a mineral powerhouse.

The actual numbers are modest compared to a glass of milk, but broccoli’s calcium comes with a twist that most people overlook. It’s not just how much calcium is in a cup of broccoli; it’s how much your body can actually use.

Calcium Content Per Cup: Raw Vs. Cooked

The number varies depending on whether the broccoli is raw, cooked, or steamed — and which source you check. University Hospitals lists a cup of raw, chopped broccoli at 42.77 mg of calcium. The Bone Health & Osteoporosis Foundation puts cooked broccoli around 60 mg per cup.

UCSF Health reports a higher figure of about 180 mg for cooked broccoli, which likely reflects a denser cup or a different cooking method. Steamed broccoli falls somewhere in the middle, at roughly 75 mg per cup according to some nutrition databases.

These gaps aren’t errors. They reflect real differences in water content, cooking time, and how tightly the cup is packed. The practical takeaway is that a serving of broccoli provides a usable amount of calcium — especially when you consider how well it absorbs.

Preparation	Calcium per Cup (Approx.)	Source
Raw, chopped	43 mg	University Hospitals
Cooked (standard reference)	60 mg	Bone Health & Osteoporosis Foundation
Cooked (UCSF figure)	~180 mg	UCSF Health
Steamed	~75 mg	School nutrition database
Broccoli rabe, cooked	98 mg	Health media sources

Why The “Calcium In Broccoli” Figure Feels Low

If you compare broccoli directly to dairy or fortified foods, the numbers look small at first glance. The context matters more than the raw milligram count.

• Oxalates change the game: Broccoli is low in oxalates, a compound that blocks calcium absorption. Spinach has more calcium per cup, but its oxalates drop absorption to roughly 10%. Broccoli’s absorption rate is much higher.
• Serving sizes are dense: A cup of cooked broccoli is about 156 grams. You absorb more calcium from that cup than from a cup of cooked spinach, despite spinach having a higher starting number.
• Bioavailability over quantity: The exact amount of calcium in broccoli is less important than the fact that your body can access 41% to 53% of it. Dairy absorbs at around 32% in some studies.
• It’s a package deal: Broccoli also provides vitamin K and magnesium, both of which support bone metabolism. Those nutrients don’t show up on a simple calcium count.

So while a cup of broccoli won’t replace a glass of milk, it delivers usable calcium alongside other bone-friendly nutrients — which is more than some higher-calcium foods can claim.

What Makes Broccoli’s Calcium Different

The science behind broccoli’s calcium is what separates it from other vegetables. Per NC State Extension, broccoli provides broccoli bone health benefits that go beyond just the mineral count. The vitamin K content helps activate proteins involved in bone formation.

Research on Brassica vegetables — which include broccoli, bok choy, and kale — shows calcium availability between 41% and 53%. That’s higher than the absorption rate from milk, which is often considered the gold standard for calcium sources.

The low oxalate content is the main reason. Oxalates are small organic acids stored as calcium oxalate crystals in plants. They bind to calcium in the digestive tract and prevent it from crossing into the bloodstream. Since broccoli stores very little oxalate, most of its calcium makes it through.

How Oxalates Affect Absorption

High-oxalate foods like spinach, chard, and beet greens can contain more total calcium per cup, but their absorption rate plummets. A 1989 study found that fractional calcium absorption from oxalate-heavy foods averaged only 10%. Broccoli, by contrast, allows for much higher bioavailability because it simply doesn’t have that built-in blocker.

How To Get The Most Calcium From Your Broccoli

A few simple choices in the kitchen can help you keep that calcium available and ready for absorption.

1. Cook lightly, don’t boil: Steaming or microwaving preserves more nutrients than boiling, which can leach minerals into the water. If you do boil, save the cooking water for soup or broth.
2. Pair with a healthy fat: Vitamin K in broccoli is fat-soluble. A drizzle of olive oil or a squeeze of lemon with a little avocado helps your body use it.
3. Don’t oversalt: High sodium intake can increase calcium excretion through urine. Keep seasoning moderate, especially if you’re already getting plenty of salt from other foods.
4. Use the stems too: The stalks contain fiber and nutrients similar to the florets. Shred or chop them into soups and stir-fries to get more volume per dollar and per nutrient.
5. Eat it with other low-oxalate greens: Combine broccoli with kale or bok choy for a cumulative calcium boost without the absorption blockers found in spinach.

None of these steps require perfect precision. Small shifts in how you prepare and pair broccoli can help your body hold onto the calcium it already contains.

Broccoli Vs. Other Calcium Sources

How does broccoli stack up against other common calcium sources? The answer depends on whether you care about total content or total absorbed calcium. The difference is significant, and it’s the reason broccoli punches above its weight in bone health conversations.

A 1989 study in PubMed found that oxalate-rich foods like spinach allow only about 10% of their calcium to be absorbed. Broccoli, being low in oxalates, allows significantly more. This is detailed in the broccoli calcium absorption study, which helps explain why plant-based eaters don’t need to obsess over raw milligram counts alone.

Food	Total Calcium per Serving	Typical Absorption Rate
1 cup cooked broccoli	~60–70 mg	41–53%
1 cup cooked spinach	~240 mg	~10%
1 cup whole milk	~300 mg	~32%
1 oz almonds	~80 mg	~20%

Broccoli isn’t the highest source on paper, but it delivers a greater percentage of its calcium to your body than many competitors. That efficiency matters for anyone relying on plants to meet their daily needs.

The Bottom Line

A cup of broccoli won’t win a calcium quantity contest against dairy or fortified foods, but it doesn’t need to. Its real strength is bioavailability: your body can use a higher percentage of the calcium it contains because broccoli is naturally low in oxalates. As of early 2026, the typical range is 43 mg for raw and 60–70 mg for cooked, though some authoritative sources report higher figures depending on density and method.

If you’re tracking calcium for bone health or following a dairy-free diet, a registered dietitian can help you balance broccoli with other sources like fortified plant milks or leafy greens to meet your specific daily target without guesswork.