My teeth is getting broken into little pieces while eating some food is that o don't have calcium or is that any other problem.

Question

Brittleness of teeth may be due to various factors:
Genetic factors: Weak teeth are sometimes passed on down the generations of a family. People belonging to these families tend to suffer brittle teeth.

Dietary habits: Eating too many sugary and acidic foods weakens teeth, and causes them to become brittle. Frequent snacking is also not advisable because the pH level of saliva does not come to its normal levels because of continuous intake of food. Usually, it takes around three to four hours for the effects of enzymes present in the food to reduce and restore optimum pH of saliva. Moreover, high acidic level in the mouth damages the enamel covering the teeth, thereby causing brittleness. Aerated drinks, much intake of citrus fruit juices like lemon, tobacco usage and too much alcohol are some of the other reasons that cause brittleness. 
Lack of balanced diets leads to vitamin and calcium deficiency in the body. As a result, teeth lose their strength and become brittle. Also, drinking water which contains high levels of fluoride is also one of the major reasons for brittleness.
Involuntary habits: Some people involuntarily grind or clench their teeth when they sleep or become emotional. When grinding happens, the outer layer or enamel covering teeth is damaged. This damage paves way to brittleness. Use of excess force while brushing teeth is another common factor for this condition.

Medical conditions: Certain diseases, not necessarily of dental origin, lead to brittle teeth. Some of the common diseases that result in this condition are:
Periodontal disease: This is a disease of the gum, jaw bones and teeth. If ignored, this disease affects the structure of dentures and strength of the gums. When the disease reaches advanced stages, teeth become brittle
Osteoporosis: Osteoporosis is not a disease of dental origin but a condition that affects the overall structure of bones in the body. People with low bone density and inadequate nutrients suffer brittle teeth through weakening of the jaw bones and teeth
Nerve changes: In some cases, nerve tissues in the teeth reduce. As a result, nervous activity in the teeth reduces. This leads to brittleness of teeth
Kidney diseases: Kidney diseases can lead to bone loss or reduced bone density. Osteoporosis is one of the side effects of some kinds of renal diseases. When kidneys malfunction, bones all over the body become weak. This affects the jaw bone as well. Teeth become loose and brittle. Also, when kidneys do not function optimally, absorption of calcium from food decreases. Teeth do not receive adequate amount of calcium and hence, become brittle.

Drugs: Certain kinds of drugs cause brittleness in bones because of the various side effects they cause. Some drugs contain ingredients that reduce calcium absorption in the body. Some drugs also contain high level of fluoride and can lead to brittleness. However, using such drugs for short durations does not cause this problem. The condition is common in people who use these drugs chronically.

Aging: Aging can also cause brittleness. Usually, the side effects of different activities, medicines and stress that the teeth undergo cumulate over age and cause brittleness as age advances. Elderly people who follow good dietary habits and avoid unhealthy habits do not suffer from brittleness.

Yasmin Asma Zohara · Accepted Answer

Brittleness of teeth may be due to various factors:
Genetic factors: Weak teeth are sometimes passed on down the generations of a family. People belonging to these families tend to suffer brittle teeth.

Dietary habits: Eating too many sugary and acidic foods weakens teeth, and causes them to become brittle. Frequent snacking is also not advisable because the pH level of saliva does not come to its normal levels because of continuous intake of food. Usually, it takes around three to four hours for the effects of enzymes present in the food to reduce and restore optimum pH of saliva. Moreover, high acidic level in the mouth damages the enamel covering the teeth, thereby causing brittleness. Aerated drinks, much intake of citrus fruit juices like lemon, tobacco usage and too much alcohol are some of the other reasons that cause brittleness. 
Lack of balanced diets leads to vitamin and calcium deficiency in the body. As a result, teeth lose their strength and become brittle. Also, drinking water which contains high levels of fluoride is also one of the major reasons for brittleness.
Involuntary habits: Some people involuntarily grind or clench their teeth when they sleep or become emotional. When grinding happens, the outer layer or enamel covering teeth is damaged. This damage paves way to brittleness. Use of excess force while brushing teeth is another common factor for this condition.

Medical conditions: Certain diseases, not necessarily of dental origin, lead to brittle teeth. Some of the common diseases that result in this condition are:
Periodontal disease: This is a disease of the gum, jaw bones and teeth. If ignored, this disease affects the structure of dentures and strength of the gums. When the disease reaches advanced stages, teeth become brittle
Osteoporosis: Osteoporosis is not a disease of dental origin but a condition that affects the overall structure of bones in the body. People with low bone density and inadequate nutrients suffer brittle teeth through weakening of the jaw bones and teeth
Nerve changes: In some cases, nerve tissues in the teeth reduce. As a result, nervous activity in the teeth reduces. This leads to brittleness of teeth
Kidney diseases: Kidney diseases can lead to bone loss or reduced bone density. Osteoporosis is one of the side effects of some kinds of renal diseases. When kidneys malfunction, bones all over the body become weak. This affects the jaw bone as well. Teeth become loose and brittle. Also, when kidneys do not function optimally, absorption of calcium from food decreases. Teeth do not receive adequate amount of calcium and hence, become brittle.

Drugs: Certain kinds of drugs cause brittleness in bones because of the various side effects they cause. Some drugs contain ingredients that reduce calcium absorption in the body. Some drugs also contain high level of fluoride and can lead to brittleness. However, using such drugs for short durations does not cause this problem. The condition is common in people who use these drugs chronically.

Aging: Aging can also cause brittleness. Usually, the side effects of different activities, medicines and stress that the teeth undergo cumulate over age and cause brittleness as age advances. Elderly people who follow good dietary habits and avoid unhealthy habits do not suffer from brittleness.