Vitamin D deficiency is quite common among people who do not get enough sunshine – such as those who work indoors, wear extensive clothing or those who are obese or aged. However, lack of vitamin D in your body can lead to several health problems such as weak bones, bone deformities, muscle cramps, fatigue and can even contribute to mental health issues. It is important to get regularly tested to determine if you lack this or any other nutrient. Your body may also tell you that you are deficient in vitamin D through various tell-tale signs. One such could be present in your mouth.