Question: what are the side effects of low vitamin d3?
Answer: Getting Sick or Infected Often. Share on Pinterest. ... 
Fatigue and Tiredness. Feeling tired can have many causes, and vitamin D deficiency may be one of them. ... 
Bone and Back Pain. ... 
Depression. ... 
Impaired Wound Healing. ... 
Bone Loss. ... 
Hair Loss. ... 
Muscle Pain.