One large egg yolk supplies about 2–3 µg of vitamin K2 (MK-4); lab data show ~15.5 µg per 100 g yolk.
Curious how much K2 hides in that golden center? Here’s the short version: researchers measuring different forms of vitamin K in common foods found that raw egg yolk contains about 15.5 micrograms of menaquinone-4 (K2, MK-4) per 100 grams of yolk. Since a typical yolk weighs only ~17 grams, you’re looking at roughly 2–3 micrograms per yolk. That’s a modest dose, but it’s steady, and it adds up across meals.
Vitamin K2 In Egg Yolks: Typical Amounts
Vitamin K shows up in two main forms in foods. Leafy greens carry phylloquinone (K1). Animal foods and some fermented foods carry menaquinones (K2). In eggs, the K2 form is MK-4. A multi-city sampling of U.S. retail foods reported the following figures for eggs. These are averaged, lab-verified numbers, not supplement claims.
| Egg Item (Raw) | Vitamin K2, MK-4 (µg/100 g) | Notes |
|---|---|---|
| Yolk | 15.5 | Primary K form in yolk is MK-4; K1 ~0.7 µg/100 g in the same dataset. |
| Whole Egg | 5.6 | Blend of white + yolk brings the average down. |
| White | 0.4 | Trace level; most K2 sits in the yolk fat matrix. |
Those values come from a joint USDA–Tufts analysis of meats, dairy, and eggs. The same research group noted that chicken, cheddar, and yolks ranked near the top within their sample set for MK-4 among animal foods. The vitamin K contents of meat, dairy, and eggs paper spells out the lab methods and the actual figures line by line.
Why Numbers Vary Between Cartons
K2 in yolks isn’t fixed. It swings based on what hens eat and how farms formulate feed. Animals can convert a feed input (menadione, a form of vitamin K used in poultry feed) into MK-4 in tissues and eggs. That means two cartons bought the same week can show different K2 levels. The vitamin K fact sheet explains these diet-driven shifts and points to feed as a driver for MK-4 showing up in poultry products.
Feed And Husbandry
Commercial feeds often include vitamin K inputs. Pasture access, insects, and greens change yolk color and fat profile, which can track with micronutrient differences. When researchers intentionally enrich feed, yolks can climb well above baseline MK-4 values. Some trials report yolk MK-4 well past the standard range when hens receive added K sources, which is one reason store brands that market “enriched” eggs can test higher than ordinary cartons.
Hen Line, Age, And Season
Breed and age influence egg composition. Warmer months can mean more forage and pigment precursors, which may correlate with yolk micronutrients in certain flocks. None of this changes the take-home message: your baseline carton still offers a steady, if small, MK-4 contribution.
How Those Lab Numbers Translate To Your Plate
Let’s turn per-100-gram lab values into real-world servings. A large yolk weighs about 17 grams. Using the 15.5 µg/100 g figure for raw yolk, the math lands near 2.6 µg per large yolk. Whole-egg numbers are lower because egg white dilutes the yolk fraction.
Serving Math, Step By Step
- Start with 15.5 µg MK-4 per 100 g raw yolk.
- Estimate yolk size: ~17 g per large egg.
- Convert: 15.5 × 0.17 ≈ 2.6 µg MK-4 per yolk.
Two yolks at breakfast? You’re in the 5 µg range. Three yolks in carbonara? Near 8 µg. That’s not a megadose, but it’s a consistent bump for daily intake.
Does Cooking Change K2 In Yolks?
Vitamin K sits in fat and shows decent heat stability across common kitchen methods. Boiling, frying, and baking change water and fat content more than they eliminate MK-4. The USDA–Tufts dataset includes cooked whole eggs with MK-4 still measurable. Scrambling in butter changes calories and texture, not the presence of MK-4 in a meaningful way for home cooks.
How Eggs Fit Into Daily K Intake
Public guidance lists adequate intake targets for total vitamin K: 90 µg for adult women and 120 µg for adult men. That figure covers all K forms combined across a day. Leafy greens carry most of that total via K1, while animal foods and fermented foods contribute K2. If you’re building a balanced day of eating, yolks play a steady supporting role for MK-4 while greens cover the bulk of total K.
Planning A Day That Includes Yolks
- Breakfast: two eggs (yolks included) for a small MK-4 bump.
- Lunch: leafy salad for K1 plus protein of choice.
- Dinner: cheese or chicken thigh adds more MK-4 alongside flavor.
Close Variation: K2 Per Egg Yolk And Practical Ranges
Readers often want a single number. Food chemistry rarely gives one. Your best estimate for a large yolk sits around 2–3 µg MK-4, with carton-to-carton movement driven by feed and farming. If you buy specialty cartons that advertise micronutrient enhancement, the per-yolk figure can run higher than the baseline lab average.
Baseline Vs. Enriched Yolks
When flocks receive extra K sources in feed, egg vitamin K rises. Trials on “K-biofortified” eggs report whole-egg vitamin K gains on the order of a few dozen micrograms per egg, which maps to a clear step up from standard cartons. Brands that pursue that route usually say so on packaging or marketing materials.
Egg Size To Yolk K2 Estimate
Use these back-of-the-envelope figures to plan recipes. Estimates assume ~15.5 µg MK-4 per 100 g yolk and typical yolk weights for each size.
| Egg Size (Typical Yolk g) | Approx. K2 Per Yolk (µg) | How This Helps |
|---|---|---|
| Medium (~15 g) | ~2.3 | Useful for baking or dressings with one yolk. |
| Large (~17 g) | ~2.6 | Standard breakfast yolk estimate. |
| Extra-Large (~19 g) | ~3.0 | Richer sauces and custards use fewer yolks for the same texture. |
Simple Ways To Capture More K2 From Yolks
Eat The Yolk
MK-4 sits in the fat of the yolk. Skipping yolks means skipping most of the K2 that eggs offer. If cholesterol is a concern, talk to your clinician about your personal targets and how many whole eggs fit your plan.
Pair With Fat
Vitamin K is fat-soluble, and eggs already bring their own fat. Cooking with olive oil, butter, or cream sauces keeps absorption conditions friendly.
Rotate Animal And Fermented Sources
Yolks add MK-4. Fermented foods can add longer-chain menaquinones, like MK-7 in natto or certain cheeses. The mix improves coverage across K forms without chasing pills.
Who Should Be Careful
People using anticoagulants need steady vitamin K intake day to day. That guidance applies to both K1 and K2. Dose changes and swings in leafy greens, cheese, or egg consumption can affect medication management. The NIH vitamin K fact sheet summarizes known drug interactions and daily targets for different age groups.
Methods Behind The Numbers
Figures in this guide come from food samples pulled in multiple U.S. cities. Analysts measured phylloquinone, dihydrophylloquinone, and menaquinone-4 by chromatography and mass spectrometry, then reported results per 100 grams. In that dataset, raw yolk averaged 15.5 µg MK-4/100 g, whole raw egg averaged 5.6 µg/100 g, and raw white showed a trace level. You can read the lab report here: Vitamin K contents of meat, dairy, and eggs. Context on forms of vitamin K, feed effects, and daily intake appears in the vitamin K fact sheet.
Practical Takeaways For Home Cooks
Breakfast And Brunch
Two eggs add protein and a small MK-4 dose. Add a side of sautéed greens for K1. Toast, avocado, or yogurt round out the plate.
Dressings And Sauces
Yolk-based dressings (Caesar style) or sauces (hollandaise, mayo) pull MK-4 into your meal while delivering texture. Use pasteurized eggs for no-cook sauces.
Batch Cooking
Quiche and frittata use several eggs at once. That bumps total MK-4 without changing your routine. Add spinach or kale to lift total K across forms.
Answers To Common Reader Questions
Is One Egg Enough For K2?
One yolk gives roughly 2–3 µg MK-4. Most daily intake comes from a mix of foods. Eggs help, but they’re one part of the picture.
Do Brown Eggs Have More K2?
Shell color tracks breed, not nutrient content. Feed and farming explain more of the K2 differences than shell color.
Do Enriched Eggs Make A Big Difference?
Feed-enriched flocks can produce eggs with higher total vitamin K. Labels and brand materials usually call this out. Expect a lift, but don’t expect a pharmacologic dose.
Bottom Line For Vitamin K2 From Egg Yolk
Plan on ~2–3 µg MK-4 per large yolk. That estimate comes from direct lab measures and simple serving conversions. If your goal is steady K intake without tracking every leaf of lettuce or each slice of cheese, keeping yolks in your meals is a straight path forward.