What Happens If I don’t Get vitamin D ? There are many issues with not having Vitamin D. Besides having weak and brittle bones, a person with vitamin D deficiency has an increased risk of having many health issues such as: Muscle weakness Cramps , Bone Weakness , Exhaustion , Depression , Hair Loss , Getting Sick Easily (Your body Can’t Fight Infections) , Pale Skin . Low Vitamin D levels have been linked to diseases like: Diabetes , Multiple sclerosis . Heart disease , High Blood pressure , Stroke