Vitamin D is an essential, fat-soluble nutrient important for overall health and well-being. Even though it is one of the most common deficiencies that people have, a lack of vitamin D can be detrimental to health. It has a lot of effects on your oral health, especially the tongue, which gives out signs that you need to understand and work on. Read on to know the five signs of vitamin D deficiency and how to get over them. , Health News, Times Now