Keep raw and cooked portions separate
ODS lists about 145 micrograms vitamin K in one cup of raw spinach. That amount should not be assigned to every spinach dish: cooked portions, packed volumes and mixed recipes can represent different quantities of leaves. [1]
A nutrient table is useful when the portion matches. It is less reliable when a loosely filled raw cup is treated as equivalent to a dense cooked serving. [1]
Consistency is the relevant dietary principle
Warfarin acts by antagonizing vitamin K activity. ODS advises maintaining consistent vitamin K intake from food and supplements because sudden changes can increase or decrease anticoagulant effects. [1]
A person who regularly eats spinach should discuss the established pattern and planned changes with the anticoagulation team. The table value does not prescribe an individual portion or an INR correction. This interaction advice is specific to warfarin-like medicines, rather than every medicine called a blood thinner. [1]
A new daily smoothie can change the pattern
Imagine someone who rarely eats greens begins a large spinach smoothie every morning. The meaningful change is the new repeated intake, not merely whether spinach appears on a forbidden-food list. Report the change during treatment review.
| Detail | Interpretation |
|---|---|
| Cup of raw spinach | About 145 micrograms |
| Cooked cup | Different portion density |
| Warfarin | Avoid abrupt intake changes |
Sources for this article
- Vitamin K - Health Professional Fact Sheet
Source consulted: 2026-09-17. This is a reference resource, not a claim that we conducted the studies or tested a product.