Surprising Signs You May Be Vitamin D Deficient

4. A weak immune system

Vitamin D plays a huge role in supporting our immune system. Unknowingly, doctors started to use this vitamin to treat infections a long time ago before antibiotics were discovered. Tuberculosis patients, for example, were sent to sanatoriums where they were exposed to sunlight which, as doctors then thought, directly killed the infection. So, if you suffer from frequent viral infections, low vitamin D levels might be the reason.