1.Association of Iron Deficiency with or without Anaemia and Cognitive Functions among Primary School Children in Malaysia
Hamid Jan JM ; Amal K Mitra ; Rohani A ; Norimah AK
Malaysian Journal of Nutrition 2010;16(2):261-270
Iron deficiency and anaemia affect millions of children worldwide. This study aimed to investigate the effect of iron deficiency with or without anaemia on
cognitive functions, specifically with short-term memory, attention and visualmotor coordination in children. A total of 173 primary school children was
enrolled. Cognitive functions were assessed using the Wechsler Intelligence Scale for Children. Three sub-tests were selected to assess processing speed
(coding test), immediate auditory memory (digit span test) and visual processing and problem solving ability (maze test). The results showed significant
correlation between age and coding test (r =0.38, p<0.001), digit span test (r =0.16,p = 0.028), and maze test scores (r =0.28, p<0.001), and the total sub-test scores (r=0.43, p <.001). After age adjustment of the cognitive function tests, iron deficient
children without anaemia scored significantly lower than the healthy children (p<0.001) on coding test, while iron deficient children with anaemia and iron
deficient children without anaemia scored significantly lower (p<0.001) than the healthy counterparts on maze test. No significant differences were observed on
digit-span score among the groups. This study confirms the negative effect of both iron deficiency and iron deficiency anaemia on processing speed and visualmotor
coordination in children.
2.Effect of Gender and Nutritional Status on Academic Achievement and Cognitive Function among Primary School Children in a Rural District in Malaysia
Hamid Jan JM ; Amal K Mitra ; Hasmiza H ; Pim CD ; Ng LO : Wan Manan WM
Malaysian Journal of Nutrition 2011;17(2):189-200
Introduction: The aim of this study was to investigate the relationship between
gender, birth weight, nutritional status, and iron status of children with their
academic performance and cognitive function. Methods: Two hundred and fortynine
children, seven to nine years of age, were recruited by systematic sampling
from six primary schools in a rural area in Malaysia. Cognitive function was
assessed by using Raven’s Coloured Progressive Matrices (R-CPM). Academic
performance of the children was recorded from their school final examination
results in four subjects including Malay language, English, Mathematics, and
Science. Birth weight was recorded from the birth certificate, and nutritional
status was determined by weight-for-age z score and height-for-age z score.
Results: Girls had a significantly higher score in all the academic tests, but a
lower cognitive score compared to boys. Nutritional status was found to be
correlated significantly with academic performance. Academic and cognitive
function scores were also found to be correlated significantly with birth weight,
parents’ education, and family income. In a multivariate analysis, gender
remained the significant predictor of academic function, and iron status and
haemoglobin were the significant predictors of cognitive function, after
controlling for other variables. Conclusion: The study showed that girls
performed better academically than boys in rural Malaysia. Nutritional status,
parents’ education and family income could be additional modifiable factors to
improve academic performance of the children. More attention is needed to
improve academic achievements of boys at their early school years.
3.Effects of occupational sunlight exposure and monsoon season on vitamin D concentration among outdoor and indoor workers in Malaysia
Norliyana Aris ; Amal K. Mitra ; Wan Mohd Izani Bin Wan Mohamed ; Wan Abdul Manan Bin Wan Muda ; Hamid Jan Bin Jan Mohamed
Malaysian Journal of Nutrition 2020;26(No.3):425-439
Introduction: Despite abundant sunshine for cutaneous vitamin D synthesis, low
levels of vitamin D have been documented among the Malaysian population. The aim
of this study was to characterise the effects of occupational sunlight exposure and
monsoon season on serum 25-hydroxyvitamin D [25(OH)D] concentration. Methods:
A comparative cross-sectional study was performed among Malay outdoor (n=119)
and indoor workers (n=119) in Kelantan. Two-point data were collected on the same
participants, first during non-monsoon season and second during the northeast
monsoon season. Data collection comprised of anthropometry measurements (body
mass index and body fat), fasting blood test [serum 25(OH)D concentration], and
questionnaire (physical activity level, sun exposure, sun protection use, and vitamin
D intake). Vitamin D classification was based on the 2011 Endocrine Society Clinical
Practice Guidelines. Results: This study found that serum 25(OH)D concentrations
were significantly higher in outdoor compared to indoor workers irrespective of
season (p<0.001) and sex (p<0.001). Monsoonal differences in serum 25(OH)D
concentration was only observed in male outdoor workers (mean difference=10.39
nmol/l, p<0.001). Significant association between vitamin D status and occupation
was also observed (p<0.001). However, no significant association was found between
vitamin D status and monsoon season [χ2(1)=0.076, p=0.783]. Conclusion: Seasonal
and occupational factors should be considered while evaluating individual serum
25(OH)D concentration and in comparing community studies, especially among
workers.