This is the 9726th most frequent Portuguese word.
cálcio
Calcium.
Here, 'cálcio' is used as the subject noun representing the chemical element important for health.
O cálcio é essencial para a formação de ossos fortes.
Calcium is essential for the formation of strong bones.
In this sentence, 'cálcio' is used as an adjective describing a specific type of supplement.
Eu comprei um suplemento de cálcio na farmácia.
I bought a calcium supplement at the pharmacy.
Again, 'cálcio' serves as a noun indicating the nutrient present in certain foods.