SERUM LEVELS OF COBALAMIN, FOLATE AND HOMOCYSTEINE IN PATIENTS WITH PSYCHIATRIC DISORDERS IN LAGOS

Abstract

Background: It is believed that the metabolism of cobalamin and folate is interrelated and
both are involved in several biochemical reactions needed for proper functioning of the brain.
It has been shown that deficiency of either vitamin can result in alteration in homocysteine
and neurotransmitters levels, thereby contributing to the onset of psychiatric disorders. We
compared homocysteine, folate and cobalamin in patients with psychiatry disorders to
mentally fit healthy controls and assessed if any association exists with these psychiatric
conditions.
Method: The cross-sectional study consisted of 230 patients with psychiatric disorders
according to ICD-10 criteria, and 230 mentally fit healthy age/sex matched controls. Full
blood count, serum homocysteine, folate and cobalamin concentrations were performed in all
participants having signed informed consents. Folate, homocysteine and cobalamin were
determined by enzyme-linked immunosorbent assay. Full blood count was determined by
Sysmex Haematology Autoanalyzer. Values were considered to be deranged if cobalamin
was < 200pg/ml, folate <3ng/ml and homocysteine > 15µmol/l.
Results: The serum levels of cobalamin in psychiatric patient group (m ± SD =
388.87±211.55 pg/ml) were significantly lower compared with the control group (m±SD =
445.53±197.96 pg/ml). p= 0.03. A significant association existed between psychiatric
disorders and cobalamin lack as 47 (20.4%) of 230 psychiatric patients had serum cobalamin
levels below 200pg/ml whereas only 25 (10.9%) of 230 control subjects had cobalamin levels
below 200pg/ml. p= 0.005. There was significant association between hyperhomocystinemia
and psychiatric illnesses as 104 (45.2%) of 230 psychiatric patients had serum homocysteine
levels above 15µmol/l whereas 81 (35.3%) of 230 control subjects had homocysteine levels
above 15µmol/l. p=0.029. The serum levels of folate in psychiatric patient group (m±SD =
10.41±6.11 ng/ml) were higher compared with the control group (m±SD = 9.93±5.32
ng/ml) although this was not significant. p>0.05. The most common psychiatric disorders in
the study were schizophrenia (64.9%) and mood disorder (32.1%). The prevalence of
cobalamin deficiency and hyperhomocystinemia in schizophrenia were 21.5% and 49%
respectively. Cobalamin deficiency was present in 22.6% of patients with depression
compared with 10.9% of controls. Most of the haematological parameters were significantly
lower in psychiatric patients compared with controls, although their means were within their
normal reference limits.
Conclusion: Study has demonstrated that cobalamin deficiency and hyperhomocystinemia
are prevalent amongst patients with psychiatric disorders.

SERUM LEVELS OF COBALAMIN, FOLATE AND HOMOCYSTEINE IN PATIENTS WITH PSYCHIATRIC DISORDERS IN LAGOS