Vitamin tablets such as vitamin A, B-complex, C and D are commonly used to support immunity, energy, nerve health, bone strength, skin health and general nutrition when dietary intake is low or a deficiency is present. They are generally safe when taken at the correct dosage and for the recommended duration prescribed by a doctor. Side effects are usually mild but may occur if vitamins are taken in excessive amounts or unnecessarily for long periods. Vitamin C may sometimes cause acidity or stomach upset, vitamin B-complex can occasionally cause nausea or bright yellow urine, vitamin D in excess may affect calcium balance, and too much vitamin A may lead to headache, liver problems, or skin issues. Taking multiple supplements together without guidance may increase the risk of overdose or unwanted effects. A balanced diet with fruits, vegetables, dairy products, nuts, eggs, fish, and sunlight exposure may naturally support vitamin levels. Consult your doctor before long-term supplement use, especially if you have kidney disease, liver disease, pregnancy, or other ongoing medical conditions.