What are some effects of taking vitamin B-12?

Taking vitamin B-12 counters the negative effects of vitamin B-12 deficiency, according to Mayo Clinic. Studies show that the mental function of infants is affected by vitamin B-12 levels during pregnancy. Vitamin B-12 use may cause harmful effects for individuals with certain health conditions.

Vitamin B-12 deficiency causes numerous symptoms and conditions including vision problems, muscle weakness, mood disturbances, megaloblastic anemia and mental problems, explains Mayo Clinic. Vitamin B-12 treatment alleviates these symptoms and conditions.

Vitamin B-12 should be used cautiously by those with high blood pressure, blood disorders, heart concerns, low serum potassium levels or gastrointestinal concerns. Others who should use vitamin B-12 cautiously are those who have skin disorders, a history of cancer, genitourinary concerns, elevated uric acid levels or a history of gout.