Which factor contributes to tooth decay?

• A. Lack of fluoride, calcium and vitamin D, and too much sugar
• B. Common in children
• C. Eat less sugar and brush teeth
• D. Eat more sugar and brush teeth

Answer: (A)

Tooth decay happens when acids made by mouth bacteria dissolve the enamel of teeth. Sugar is the fuel for those bacteria, so frequent or high sugar intake leads to more acid production and more demineralization. Fluoride helps repair early damage by promoting remineralization and also can slow bacterial acid production. Calcium is the mineral teeth are made from, and vitamin D helps the body absorb calcium and keep bones and teeth strong. When fluoride, calcium, and vitamin D are lacking, teeth become more vulnerable to acid attack, and too much sugar makes this damage more likely.

So this option correctly brings together the key factors that contribute to decay: insufficient fluoride, calcium, and vitamin D, along with excessive sugar. The other statements don’t identify the causes as directly: being common in children is about prevalence, not cause; eating less sugar and brushing reduces risk; eating more sugar and brushing may still reduce some risk due to brushing, so it doesn’t pin down the contributing factors as clearly.