Clinical Note: I have my patients target an optimal serum homocysteine of 6.0 (even though the “acceptable” higher range is often upwards of 11).
In 2002, a study published in the American Journal of Psychiatry examined 3,884 elderly people for symptoms relating to mood and cognitive function, folate, vitamin B12 and homocysteine blood levels. The results were that high homocysteine levels, vitamin B12 deficiency and, to a lesser extent, folate deficiency all corresponded to symptoms relating to moodiness and a lesser degree of cognitive function. Other research has found similar results.
The mechanism of action seems to be related to homocysteine’s alteration of neurotransmitters.
References:
Tiemeier H, van Tuijl HR, Hofman A, et al. Vitamin B12, Folate, and Homocysteine in Depression: The Rotterdam Study. Am J Psychiatry 2002;159:2099–2101.
Kim J-M, Stewart R, Kim S-W, et al. Predictive value of folate, vitamin B12 and homocysteine levels in late-life depression. Br J Psychiatry 2008;192: 268–274.
Bjorkegren K, Svardsudd. Elevated serum levels of methylmalonic acid and homocysteine in elderly people. A population-based intervention study. J Intern Med 1999; 246(3):317-24.
Rasmussen K, Moller J, Lyngbak M. Within-person variation of plasma homocysteine and effects of posture and tourniquet application. Clin Chem 1999; 45(10):1850-5.
