From a global perspective, vitamin deficiency is a growing problem with approximately 2 billion people vitamin deficient. Common types of vitamin deficiency are B12, biotin, calcium, iodine, iron, magnesium, niacin, Vitamin A, Vitamin C, Vitamin D, and zinc, and it is important that people make sure they are receiving the recommended daily amount (RDA) of each. If you experience symptoms like bleeding gums, dry skin, hair loss, or muscle cramps, you could be experiencing vitamin deficiency. To improve your vitamin deficiency, eat plenty of fruits and vegetables, limit smoking, and take supplements for specific nutrients. Take time to learn about vitamin deficiency so you can ensure you are receiving enough nutrients.