Strong tooth enamel is the result of proper balance of minerals, especially calcium in its structure. Vitamin D plays a key role in the absorption and transfer of calcium to the dental tissue, and its deficiency causes a chain of oral and dental problems. Next, we will examine the effect of vitamin D and calcium deficiency on the strength of teeth. **The role of calcium in tooth structure** Calcium is the most important mineral component in tooth enamel and constitutes approximately 96% of its weight. The presence of sufficient calcium makes tooth enamel strong and resistant to chewing pressure and bacterial acids. Without proper storage of calcium, tooth enamel becomes brittle and prone to fracture. This small amount of calcium reduction can accelerate the decay process. Therefore, daily supply of calcium through diet is important and necessary. The importance of vitamin D in calcium absorption Vitamin D acts as the key to regulate calcium absorption in the intestine and facilitates its storage in bones and teeth. Without the presence of vitamin D, even adequate intake of calcium in the diet will not be effective for strengthening teeth. By activating specific receptors in intestinal cells, this vitamin increases the amount of calcium transfer to the blood circulation. In addition, vitamin D is also effective in regulating phosphorus levels, which together with calcium leads to the formation of hydroxyapatite in teeth. As a result, vitamin D deficiency actually limits calcium absorption and threatens the health of tooth enamel **Mechanisms of vitamin D and calcium deficiency and its complications** - ### **Decreasing the density of tooth enamel:** Deficiency of calcium alone or following the reduction of vitamin D, leads to the erosion of enamel and the thinning of the protective layer on the teeth. As the enamel becomes thinner, the tooth becomes more vulnerable to wear and decay. - ### **Increasing the risk of caries:** The acidic surface of the bacterial plaque quickly dissolves the tooth enamel with the help of the thinner layer of enamel and creates cavities. The natural resistance of enamel is reduced and the destruction process becomes faster. Also **effect of drinking water on tooth decay** should be considered. - ### **Tooth sensitivity:** The reduction of calcium and the decay of the dentin under the enamel causes the sensitive dentin to appear. In this case, the tooth reacts painfully to cold, heat or chewing pressure and affects the patient's quality of life. - ### **Periodontitis and jaw bone loss: Lack of calcium and vitamin D not only damages tooth enamel but also reduces jaw bone density. As a result, the gums are degraded and the possibility of tooth loosening or periodontal infections increases. **Effective factors in vitamin D and calcium deficiency** - ### **Unbalanced diet:** Inadequate consumption of dairy products, leafy vegetables and foods rich in calcium or vitamin D sources such as fatty fish and egg yolks increases the risk of deficiency. - ### **Sedentary lifestyle and low sun exposure:** Lack of exposure to direct sunlight (the main source of vitamin D synthesis) and inactivity reduce vitamin D absorption. - ### **Specific physiological conditions: During pregnancy, breastfeeding, childhood and menopause, when the need for calcium and vitamin D is greater, the possibility of deficiency also increases. - ### **Digestive problems: Intestinal absorption disorders such as celiac disease or chronic intestinal inflammation cause a powerful reduction in the absorption of minerals from the diet. Warning signs of vitamin D and calcium deficiency - The brittle appearance of the teeth - Pain or sudden sensitivity to temperature changes - Unusual gingival bleeding or resorption - Decreasing the quality and strength of dental prostheses in implant patients - Frequent breakage of tooth enamel or its filling Early detection of these symptoms and visiting a dentist or nutritionist to test serum levels of calcium and vitamin D can prevent many serious complications. **Methods to prevent and strengthen vitamin D and calcium** 1. ### **Nutrition rich in calcium** - Low-fat dairy products, green leafy vegetables, almonds and tofu - Regular consumption of calcium supplements after medical advice 2. ### **supplying enough vitamin D** - 15-20 minutes of daily sun exposure - Vitamin D3 supplements with appropriate dosage based on age and health conditions 3. ### **Strengthening oral and dental health** - Using toothpastes and mouthwash containing fluoride - Regular brushing with basic technique and flossing 4. ### **Periodic medical examination** - Six-month dental examinations to monitor tooth enamel health - Blood tests to control calcium and vitamin D levels ### **Summary** Calcium and vitamin D deficiency not only compromises general bone health, but also weakens the foundations of tooth strength and enamel. Following a calcium-rich diet, regular supply of vitamin D through sunlight or supplements, and careful oral care can prevent serious dental damage and maintain a healthy smile. ### **