TONY K. W. NG AND Y. H. CHONG
Serum Vitamin A Levels of Two Rural Communities in Malaysia* by TONY K. W. NG, B.Sc. (Hons.) and Y. H. CHONG, B.Sc (Hons.), Ph.D., M.I.Biol., F.R.I.C. Division of Nutrition, Institute for Medical Research, Kuala Lumpur.
Acknowledgements *Blood specimens for this study, except those of the kindergarten children of Jenderam Hilir and Kampong Bahagia, were provided per courtesy of the Division of Rural Health and Behavioural Sciences of this Institute. The Farrand Spectrofluorometer used in this study was purchased from SEAMEO TROPMED funds.
Materials and methods Ulu Rening and Sungai Choh are two closelysituated villages about 35 miles north of the capital city, Kuala Lumpur. The former was wholely a Malay community with a population of 429 while the latter was predominantly an Indian community with a population of 1,217. The chief occupation in both communities was rubber tapping. 407 subjects of both sexes from the two villages were examined. They comprised 60 pre-school children, 149 school children and 198 adults. Blood was collected by disposable plastic syringes and in some cases of pre-school children, by heparinised capillary tubes. The sera were separated less than 24 hours after blood collection and stored immediately at -20°C. Serum vitamin A levels were determined by the micro-fluorometric procedure of Garry et al.s using a silicic acid column to remove contaminating fluorescence. Retinol (Sigma) was used as standard and fluorometry was carried out on a Farrand Spectrofluorometer Mk I. Results and discussion The serum vitamin A levels of the 3 age-groups in Ulu Rening and Sungai Choh are presented in Table I and the frequency distribution of the serum levels in Figs. 1-4.
Table I Serum vitamin A levels in the 3 age-groups in Ulu Rening and Sungai Choh , Selangor Age-group
No. of subjects
Mean age (yr)
Serum vit. A Mean + SD Mg/dl
Ulu Rening (1975)
pre-school school adults
38 69 89
4 11 36
Sungai Choh (1975-76)
pre-school school adults
22 80 109
4* 12 32
**prc-school
32
' Rural community
Jenderam Hilir and Kampong Bahagia
*% "at risk"
%with eye lesions
25+8' 32+11 42±11
32 16 3
NU Nil Nil
24+6 26+11 36±13
32 27 7
NU NU Nil
33±6
0
NU
'Subjects with serum vitamin A levels less than 20 p g/dl •'Children were on supplementary feeding. Environmental Child Health, April 1977
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Vitamin A deficiency has long been recognised as a major nutritional.problem in developing nations and the main cause of preventable blindness.1 The deficiency often accompanies protein-caloriemalnutrition and can be precipitated or aggravated by attacks of diarrhoea and parasitic infestations. Despite the abundance of a variety of carotene-rich, green, leafy vegetables and pigmented fruits in Malaysia, the diet of the rural toddlers in particular is well-known for their inadequacy of the pro-vitamin A. This is further aggravated by restriction of intake of the pre-formed vitamin owing to the unavailability and the relatively higher-cost of foods of animal origin.2 3 4 Clinical eye lesions, a late manifestation of vitamin A deficiency, are the only reliable signs of diagnosing the deficiency in man. However, serum vitamin A levels can serve as an early warning system of a population's risk to hypovitaminosis A. This paper reports the serum vitamin A levels of two rural communities in the state of Selangor, Malaysia.
TONY, K. W. NG A N D Y. H. CHONG
1
70
1
60
L
•
ULU ttENING ( n = i 9 6 )
H
B
SUNGM CHOH ( n = 211 )
1 1 1
j it
o
dumber
IS JO 20
0
•
0-9
10-19
1—1
20-29 30-39 40-49 50-59 60-69 Serum vitamin A (jugfelt)
I •
( n = 38 )
SUNGAI CHOH ( n = 22 )
1 1 3 70
Fig. 1 Frequency distribution of serum vitamin A levels in all agegroups
40
I ULU RENING
•
0-9 10-19 20-29 30-39 40-49 Serum vitamin A ( jjg /dl ) Fig. 2 ' Frequency distribution of serum vitamin A levels in preschool children
I ULU RENING ( n = 69 ) SUNGAI CHOH ( n = B0 )
ULU KCNiNa ( n = 89 ) SUNCAI CHOH ( n 1 1 0 9 )
o 30
u 30
S" -20
JlO 0-9
10-19 20-29 30-39 40-49 50-59 Serum vitamin A ( x i g / d l )
60-69
0-9
10-19
20-29
30-39
40-49
Serum vitamin A
50-59
60-69
a 70
(jjg/dl)
Fig. 3 Frequency distribution of serum vitamin A levels in school children
Fig. 4 Frequency distribution of serum vitamin A levels in adults
Vitamin A deficiency may be considered a serious nutritional problem in a population group when 15% or more of the subjects surveyed have serum vitamin A levels less than 20 (Jig/dl, or 5% or more possess serum levels less than 10 pg/dl, or both.6 Hence subjects with a serum vitamin A level of less than 20 pg/dl may be regarded as "at risk". This arbitrary rutoff point for indicating vitamin A nutriture seems appropriate in the present context since 20 recent hospital cases with clinical eye lesions studied in this laboratory exhibited a mean level of 15 pg/dl by the same analytical procedure.7
found for army, Malay toddlers,8 32% of the subjects in both communities had levels below 20 pg/dl. Despite this moderately high prevalence of hypovitaminosis A, none of the subjects had serum levels in the seriously deficient range, namely below 10 pg/dl. Furthermore, no clinical eye lesions were evident in "at risk" subjects which suggests that the vitamin A status encountered in this age-group, although unsatisfactory by the criteria of the Pan American Health Organisation,6 was superior to that. found in the same age-group in Ulu Trengganu where extremes of hypovitaminosis A were reported and clinical eye lesions in deficient subjects were not uncommon.3 4 * In contrast, 32 kindergarten children from two other villages in Selangor, Jenderam Hilir and Kampong Bahagia, who were under a supplementary feeding programme^ exhibited very satisfactory serum vitamin A levels with a mean of 33
Pre-school children
The pre-school children of Ulu Rening and Sungai Choh possessed closely-similar mean serum vitamin A levels of 25 pg/dl and 24 pg/dl respectively. Although these levels are only slightly lower than the 29 pg/dl 92
Environmental Child Health, April 1977
Downloaded from http://tropej.oxfordjournals.org/ at University of Glasgow on June 26, 2015
10
J1 11 1I 11 1 1 I
I
TONY. K. W. NG A N D Y. H. CHONO
pg/dl by the same analytical procedure. None of these latter subjects could be regarded as "at risk".9 School children 16% and 27% of the Malay and Indian school children respectively were found to have low serum vitamin A levels. However, clinical eye lesions were absent in "at risk" subjects although 3.7% of them in Sungai Choh had serum vitamin A levels below 10 pg/dl. By comparison, about 50% of over 200 primary school children in Ulu Trengganu had serum levels below 20 pg/dl with a mean level of 22 pg/dl.4
Summary and conclusions Serum vitamin A levels were determined for a Malay and an Indian community in rural Malaysia. 32% of the pre-school children of both communities had serum vitamin A levels that may be regarded as "at risk", namely levels below 20 pg/dl, while 16% and 27% of the Malay and Indian school children
Environmental Child Health, April 1977
References 1. Holmes, W. J. (1973) Blindness due to vitamin A deficiency. / . Trop. Pedia, and Environ. Child. Hlth., 19, 89. 2. Thomson, F. A. (1960) Child Nurtition — A survey in the Parit District of Perak, Federation of Malaya. Bull. 10 Inst. Med. Res., Fed. Mai. 3. Chen, P. C. Y. (1972) Socioculturaj influences on vitamin A deficiency in a rural communtiy. J. Trop. Med. and Hyg., 75, 231. 4. Chandrasekharan, N. (1975) Ecological assessment of vitamin A status of primary school children in Ulu Trengganu. Med. J. Mai, 29, 187. 5. Garry, J. J., Pollack J. D. and Owen G. M. (1970) Plasma vitamin A byfluorometryand use of a silicic acid column technique. Clin. Chem., 16, 766. 6. Chopra, J. G., and Kevany J. (1970) Report of the Expert Group on Hypovitaminosis A. Pan American Health Organisation. Am. J. Clin. Nutr., 23, 231. 7. Nutrition Division, Inst. Med. Res., Kuala Lumpur; unpublished results. 8. Chong, Y. H., McKay, D. A., Lim, R. K. H. (1972) Some results of recent nutrition surveys in West Malaysia. Bull. Pub. Health. Soc, 6, 55. 9. I.M.R., Kuala Lumpur; unpublished results.
93
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Adults The serum vitamin A levels of the rural adult population of both communities were satisfactory and did not appear to be "at risk" to hypovitaminosis A. They possessed comparatively high mean serum vitamin A levels; 42 pg/dl in Ulu Rening and 36 pg/dl in Sungai Choh.
respectively were found to be in a similar state of hypovitaminosis A. These findings provide further support for the existence of a serious vitamin A nutritional problem amongst rural Malaysian youth. In contrast the rural adult population did not appear to suffer any measurable lack of this vitamin.
Serum Vitamin A Levels of Two Rural Communities in Malaysia* by TONY K. W. NG, B.Sc. (Hons.) and Y. H. CHONG, B.Sc (Hons.), Ph.D., M.I.Biol., F.R.I.C. Division of Nutrition, Institute for Medical Research, Kuala Lumpur.
Acknowledgements *Blood specimens for this study, except those of the kindergarten children of Jenderam Hilir and Kampong Bahagia, were provided per courtesy of the Division of Rural Health and Behavioural Sciences of this Institute. The Farrand Spectrofluorometer used in this study was purchased from SEAMEO TROPMED funds.
Materials and methods Ulu Rening and Sungai Choh are two closelysituated villages about 35 miles north of the capital city, Kuala Lumpur. The former was wholely a Malay community with a population of 429 while the latter was predominantly an Indian community with a population of 1,217. The chief occupation in both communities was rubber tapping. 407 subjects of both sexes from the two villages were examined. They comprised 60 pre-school children, 149 school children and 198 adults. Blood was collected by disposable plastic syringes and in some cases of pre-school children, by heparinised capillary tubes. The sera were separated less than 24 hours after blood collection and stored immediately at -20°C. Serum vitamin A levels were determined by the micro-fluorometric procedure of Garry et al.s using a silicic acid column to remove contaminating fluorescence. Retinol (Sigma) was used as standard and fluorometry was carried out on a Farrand Spectrofluorometer Mk I. Results and discussion The serum vitamin A levels of the 3 age-groups in Ulu Rening and Sungai Choh are presented in Table I and the frequency distribution of the serum levels in Figs. 1-4.
Table I Serum vitamin A levels in the 3 age-groups in Ulu Rening and Sungai Choh , Selangor Age-group
No. of subjects
Mean age (yr)
Serum vit. A Mean + SD Mg/dl
Ulu Rening (1975)
pre-school school adults
38 69 89
4 11 36
Sungai Choh (1975-76)
pre-school school adults
22 80 109
4* 12 32
**prc-school
32
' Rural community
Jenderam Hilir and Kampong Bahagia
*% "at risk"
%with eye lesions
25+8' 32+11 42±11
32 16 3
NU Nil Nil
24+6 26+11 36±13
32 27 7
NU NU Nil
33±6
0
NU
'Subjects with serum vitamin A levels less than 20 p g/dl •'Children were on supplementary feeding. Environmental Child Health, April 1977
91
Downloaded from http://tropej.oxfordjournals.org/ at University of Glasgow on June 26, 2015
Vitamin A deficiency has long been recognised as a major nutritional.problem in developing nations and the main cause of preventable blindness.1 The deficiency often accompanies protein-caloriemalnutrition and can be precipitated or aggravated by attacks of diarrhoea and parasitic infestations. Despite the abundance of a variety of carotene-rich, green, leafy vegetables and pigmented fruits in Malaysia, the diet of the rural toddlers in particular is well-known for their inadequacy of the pro-vitamin A. This is further aggravated by restriction of intake of the pre-formed vitamin owing to the unavailability and the relatively higher-cost of foods of animal origin.2 3 4 Clinical eye lesions, a late manifestation of vitamin A deficiency, are the only reliable signs of diagnosing the deficiency in man. However, serum vitamin A levels can serve as an early warning system of a population's risk to hypovitaminosis A. This paper reports the serum vitamin A levels of two rural communities in the state of Selangor, Malaysia.
TONY, K. W. NG A N D Y. H. CHONG
1
70
1
60
L
•
ULU ttENING ( n = i 9 6 )
H
B
SUNGM CHOH ( n = 211 )
1 1 1
j it
o
dumber
IS JO 20
0
•
0-9
10-19
1—1
20-29 30-39 40-49 50-59 60-69 Serum vitamin A (jugfelt)
I •
( n = 38 )
SUNGAI CHOH ( n = 22 )
1 1 3 70
Fig. 1 Frequency distribution of serum vitamin A levels in all agegroups
40
I ULU RENING
•
0-9 10-19 20-29 30-39 40-49 Serum vitamin A ( jjg /dl ) Fig. 2 ' Frequency distribution of serum vitamin A levels in preschool children
I ULU RENING ( n = 69 ) SUNGAI CHOH ( n = B0 )
ULU KCNiNa ( n = 89 ) SUNCAI CHOH ( n 1 1 0 9 )
o 30
u 30
S" -20
JlO 0-9
10-19 20-29 30-39 40-49 50-59 Serum vitamin A ( x i g / d l )
60-69
0-9
10-19
20-29
30-39
40-49
Serum vitamin A
50-59
60-69
a 70
(jjg/dl)
Fig. 3 Frequency distribution of serum vitamin A levels in school children
Fig. 4 Frequency distribution of serum vitamin A levels in adults
Vitamin A deficiency may be considered a serious nutritional problem in a population group when 15% or more of the subjects surveyed have serum vitamin A levels less than 20 (Jig/dl, or 5% or more possess serum levels less than 10 pg/dl, or both.6 Hence subjects with a serum vitamin A level of less than 20 pg/dl may be regarded as "at risk". This arbitrary rutoff point for indicating vitamin A nutriture seems appropriate in the present context since 20 recent hospital cases with clinical eye lesions studied in this laboratory exhibited a mean level of 15 pg/dl by the same analytical procedure.7
found for army, Malay toddlers,8 32% of the subjects in both communities had levels below 20 pg/dl. Despite this moderately high prevalence of hypovitaminosis A, none of the subjects had serum levels in the seriously deficient range, namely below 10 pg/dl. Furthermore, no clinical eye lesions were evident in "at risk" subjects which suggests that the vitamin A status encountered in this age-group, although unsatisfactory by the criteria of the Pan American Health Organisation,6 was superior to that. found in the same age-group in Ulu Trengganu where extremes of hypovitaminosis A were reported and clinical eye lesions in deficient subjects were not uncommon.3 4 * In contrast, 32 kindergarten children from two other villages in Selangor, Jenderam Hilir and Kampong Bahagia, who were under a supplementary feeding programme^ exhibited very satisfactory serum vitamin A levels with a mean of 33
Pre-school children
The pre-school children of Ulu Rening and Sungai Choh possessed closely-similar mean serum vitamin A levels of 25 pg/dl and 24 pg/dl respectively. Although these levels are only slightly lower than the 29 pg/dl 92
Environmental Child Health, April 1977
Downloaded from http://tropej.oxfordjournals.org/ at University of Glasgow on June 26, 2015
10
J1 11 1I 11 1 1 I
I
TONY. K. W. NG A N D Y. H. CHONO
pg/dl by the same analytical procedure. None of these latter subjects could be regarded as "at risk".9 School children 16% and 27% of the Malay and Indian school children respectively were found to have low serum vitamin A levels. However, clinical eye lesions were absent in "at risk" subjects although 3.7% of them in Sungai Choh had serum vitamin A levels below 10 pg/dl. By comparison, about 50% of over 200 primary school children in Ulu Trengganu had serum levels below 20 pg/dl with a mean level of 22 pg/dl.4
Summary and conclusions Serum vitamin A levels were determined for a Malay and an Indian community in rural Malaysia. 32% of the pre-school children of both communities had serum vitamin A levels that may be regarded as "at risk", namely levels below 20 pg/dl, while 16% and 27% of the Malay and Indian school children
Environmental Child Health, April 1977
References 1. Holmes, W. J. (1973) Blindness due to vitamin A deficiency. / . Trop. Pedia, and Environ. Child. Hlth., 19, 89. 2. Thomson, F. A. (1960) Child Nurtition — A survey in the Parit District of Perak, Federation of Malaya. Bull. 10 Inst. Med. Res., Fed. Mai. 3. Chen, P. C. Y. (1972) Socioculturaj influences on vitamin A deficiency in a rural communtiy. J. Trop. Med. and Hyg., 75, 231. 4. Chandrasekharan, N. (1975) Ecological assessment of vitamin A status of primary school children in Ulu Trengganu. Med. J. Mai, 29, 187. 5. Garry, J. J., Pollack J. D. and Owen G. M. (1970) Plasma vitamin A byfluorometryand use of a silicic acid column technique. Clin. Chem., 16, 766. 6. Chopra, J. G., and Kevany J. (1970) Report of the Expert Group on Hypovitaminosis A. Pan American Health Organisation. Am. J. Clin. Nutr., 23, 231. 7. Nutrition Division, Inst. Med. Res., Kuala Lumpur; unpublished results. 8. Chong, Y. H., McKay, D. A., Lim, R. K. H. (1972) Some results of recent nutrition surveys in West Malaysia. Bull. Pub. Health. Soc, 6, 55. 9. I.M.R., Kuala Lumpur; unpublished results.
93
Downloaded from http://tropej.oxfordjournals.org/ at University of Glasgow on June 26, 2015
Adults The serum vitamin A levels of the rural adult population of both communities were satisfactory and did not appear to be "at risk" to hypovitaminosis A. They possessed comparatively high mean serum vitamin A levels; 42 pg/dl in Ulu Rening and 36 pg/dl in Sungai Choh.
respectively were found to be in a similar state of hypovitaminosis A. These findings provide further support for the existence of a serious vitamin A nutritional problem amongst rural Malaysian youth. In contrast the rural adult population did not appear to suffer any measurable lack of this vitamin.
