Bleeding of Gums and Loosening of Teeth is Caused due to Deficiency of:

Vitamin C

Bleeding of Gums and Loosening of Teeth is Caused due to Deficiency of Vitamin C. This condition is a type of a Periodontal Diseases (Gingivitis) also known as scurvy. The symptoms are bleeding gums, loosening of teeth, swollen and painful joints, bleeding in tissues and general fatigue.
There are the  some risk factors for gingivitis:

• Smoking or Chewing Tobacco
• Diabetes
• Crooked Teeth
• Genetic factors
• Compromised immunity (Such as HIV/AIDS)

Scurvy or subclinical scurvy is caused by the lack of Vitamin C. Vitamin C is important for collagen formation and helps to maintain the integrity of skin and connective tissue, bone, blood vessel walls and dentine. Scurvy can be treated by eating vitamin C-rich foods like orange, papaya, strawberries and lemons