Best Calcium-Rich Foods for Chickens

Ranked by calcium content among foods safe for chickens in the Creature Feast catalog.

Kale per 100g raw: 150mg calcium (low oxalate, high bioavailability) Kale is the standout vegetable calcium source for laying hens because its calcium is highly bioavailable due to very low oxalate levels. Unlike spinach, where oxalic acid binds much of the calcium and renders it useless, kale delivers calcium that actually reaches the hen's bloodstream for eggshell formation.

Bok Choy per 100g: 105mg calcium (~54% bioavailability) Bok choy delivers calcium with over 50% absorption efficiency, making it one of the most bioavailable vegetable calcium sources for poultry. The mild flavor means even picky hens tend to eat it willingly, and it can be floated in water dishes on hot days for a cooling calcium-rich treat.

Broccoli per 100g raw: 47mg calcium, plus 102mcg Vitamin K Broccoli provides moderate calcium along with Vitamin K, which supports the calcium-binding proteins involved in bone metabolism. Both florets and chopped stems are eagerly consumed by chickens and can be hung in the run for enrichment that doubles as calcium supplementation.

Spinach per 100g raw: 99mg calcium (but ~95% bound by oxalates) Spinach contains substantial calcium on paper, but its high oxalic acid content binds roughly 95% of that calcium, making it largely unavailable for absorption. It should be fed in moderation to laying hens and never relied upon as a primary calcium source. Limit to 2-3 times per week alongside genuinely bioavailable calcium sources.

Romaine Lettuce per 100g: 33mg calcium Romaine lettuce provides a modest amount of calcium with reasonable bioavailability. While not a concentrated source, its high water content makes it a hydrating treat that contributes some calcium during hot weather when hens may reduce feed intake but still need minerals for shell formation.