I was asked if sardines if that are tinned in different sauces have different amounts of calcium.
Quick answer
There is a small difference in the calcium content. But this could be because sardines vary so it may be different between brands.
Long answer
Sardines are a good, non-dairy source of calcium. The sardine bones are soft which makes them easy to eat.
I could not find exact amounts of calcium. But the amount of calcium in sardines varies; it is around 500mg per 100g.
Sardines in oil : 569 mg of calcium
Sardines in tomato sauce: 430mg (4 fish with bones)* this may not be 100g of sardines