She was suggested to increase calcium phosphate and reduce soda content because acidic soda dissolves the calcium phosphate of the teeth.
Step-by-step explanation:
Calcium phosphate is an important mineral which keeps the teeth firm and strong. If calcium phosphate is not present in adequate quantity it will cause the teeth to become soft and easy for cavities to get formed.
Calcium phosphate naturally repairs the teeth by remineralization process.
Soda contains phosphoric and citric acids which dissolve the protective layer of calcium phosphate of the teeth and makes it brittle causing increased cavities.