What is the primary cause of homocysteine accumulation in the blood, leading to hyperhomocysteinemia?

A Deficiency of vitamin B12
B Deficiency of vitamin B6
C Deficiency of folate
D All of the above ✓
Hyperhomocysteinemia can be caused by deficiencies in vitamin B12, vitamin B6, or folate, as these vitamins are essential for the metabolism of homocysteine.
B12, B6, and Folate - 'BBF' to remember
National Institutes of Health
Metabolic and Nutritional Disorders Metabolic Disorders Amino Acid Metabolism Medium MEDICAL Confidence: high