Role of vitamin B 12, folate, and thyroid stimulating hormone in dementia: A hospital-based study in north Indian population

Background: Vitamin B 12 and folate represent modifiable risk factors for dementia. They may increase the risk of Alzheimers dementia (AD) and vascular dementia (VaD) as their deficiency can increase the homocysteine level due to slowed methylation reaction. Homocysteine has a neurotoxic effect that could lead to neurologic disturbances. Hence, it is important to explore the status of serum B 12 and folate in AD and VaD to evolve the treatment strategies for the same. Objectives: A retrospective study was conducted to assess the levels of vitamin B 12 , folate, and thyroid stimulating hormone (TSH) in serum and the relationship of these factors, including age and sex to cognitive decline in VaD, AD, and dementia due to other causes (DOC). Materials and Methods: Serum vitamin B 12 , folate, TSH, and total cholesterol were studied in 32 AD patients (mean age: 65 years), 12 VaD patients (mean age: 61 years), 83 DOC (mean age: 65 years), and 127 control subjects (mean age: 49 years). Results: In AD, VaD, and DOC, the levels of vitamin B 12 and folate were significantly lower (P < 0.002; 0.026; 0.002 for vitamin B 12 and P < 0.000 in all the 3 groups for folate) as compared with the controls. Similarly, TSH levels were significantly lower in AD and DOC (P < 0.008; 0.038) as compared with the controls. Conclusion: Vitamin B 12 and folate were significantly low in both AD and VaD patients. Hence, B vitamin supplementation should be considered as possible targets for the therapeutic intervention in dementia.