Vitamin B 12 levels in healthy infants aged 3-6 months

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Vitamin B 12 levels in healthy infants aged 3-6 months

Divya Dave

, Rahul Badheka

1_{Associate Professor, Department of Pediatrics, G.M.E.R.S. Medical College, Gotri, Vadodara,} 2_{Resident, Medical College, Vadodara}

INTRODUCTION

Anemia is the commonest cofactor encountered in pediatric patients in both indoor as well as office practice. A child is said to be anemic when the hemoglobin and/or hematocrit is two standard deviations below the mean for that particular age and sex. (1) Anemia is a serious concern for young children because it can result in impaired cognitive performance, behavioral and motor development, coordination, language development, and scholastic achievement as well as increased morbidity from infectious diseases. One of the most vulnerable groups is 6-24 months of age. (2) From public health viewpoint, nutritional deficiencies accounts for most of the anemic cases.(3)NFHS-3 survey shows that the incidence of anemia in children aged 6-35 months is 79.2% with 72.7% in urban areas and 81.2% in rural areas.(4) Megaloblastic anemia is more prevalent among nutritionally challenged pediatric populations in tropical and subtropical countries where it is seen mainly in the age group of 3-18 months in association with maternal deficiencies and prolonged breast feeding.(5) Aims of the Study: To assess the presence of anemia in healthy infants aged 3-6 months visiting the well

*Corresponding Author

Dr. Divya Dave,

B-5, Vidyakunj Society, Opp. Bhathuji Temple Manjalpur, Vadodara

Email:- drdivya99@yahoo.com

baby clinic and to find out the presence of vitamin B12 deficiency in the study group.

MATERIALS AND METHODS

The study was conducted over a period of six months in the Department of Pediatrics, SSGH, a tertiary level hospital and Government Medical College, Vadodara. 100 healthy infants in the age group of 3-6 months presenting to Well Baby Clinic were enrolled in a cross-sectional study. A detailed bio-data of the patient including name, age, sex, caste, address, the parent’s occupation, education & income was taken by oral questionnaire method. A note of the presenting complaints along with relevant family and past history was taken at the time of enrollment. Detailed antenatal history of mother, birth history and feeding history of infant with due stress to history of milk intake with history of supplements, multivitamin and iron and dietary intake of mother were noted. Each child was evaluated for the presence of cognitive dysfunction and developmental delay if any. A written and informed consent was taken of infant’s parents for participation in the study and with drawing blood sample for hemoglobin and vitamin B12 level. A

thorough head to toe examination of the infant especially assessing for status of nutrition, signs of vitamin/ micronutrient deficiency, signs suggestive of CCF, any organomegaly and other associated co morbidities was done. Samples were collected by

ORIGINAL ARTICLE

ABSTRACT

BACKGROUND: Anaemia is a global problem of immense public health significance. A child is said to be

anaemic when the haemoglobin and/or hematocrit is two standard deviations below the mean for that particular age and sex. Aims: To assess the presence of anaemia in healthy infants aged 3-6 months visiting the well baby clinic and to find out presence of Vitamin B12 deficiency in the study group. MATERIALS AND METHODS: 100 healthy infants in the age group of 3-6 months presenting to Well Baby Clinic were enrolledin a cross sectional study. RESULTS: During the study 100 infants in the age group of 3-6 months had been examined and investigated in the Well Baby Clinic for vitamin B12 deficiency and anaemia. All over 82% of infants were found

anaemic among 3-6 months age group. 60.2% of infants with anaemia had vitamin B 12 deficiency while 29.4% infants without anaemia had associated Vitamin B12 deficiency. Vitamin B12 deficiency increases as the age group

advances. However, as this study sample is small, it needs to be evaluated on a large study group before considering it as significant. Odds ratio revealed that chances of developing B12 deficiency in children with

vegetarian mothers is 2.3 times higher than those compared with non vegetarian mother. In our study, it was found that, among the 55 infants deficient for vitamin B12 , 44 of them has microcytic RBCs,9 have normocytic RBCs and

2 have macrocytic RBCs. Therefore, though the infants are deficient for vitamin B12, they have associated

micocytic anaemia. CONCLUSION: The axis of maternal malnutrition, vegetarian mother, and prolonged exclusive breast-feeding predisposes to the development of Vitamin B12 deficiency.

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venous puncture, 1 ml for Complete Blood Count and 2 ml for Serum B12 level estimation and send to

the assigned laboratory. Fully automated blood analyzer did hemoglobin and indices. Serum B12

levels was estimated by the AXSYM system, which is a Micro particle Enzyme Immunoassay for the quantitative determination of vitamin B12 in human

serum or plasma. Inclusion criteria for the study:

The study group comprised of normal healthy infants between the age group of 3-6 months visiting the Well Baby Clinic.( Birth weight >2.5 kg, no perinatal insult, normal neonatal period) Exclusion Criteria: Hospitalized infants and infants visiting High-risk clinic in the above age group were not considered as a part of this study. Criteria adopted for the study:

1. Each child was assigned a socioeconomic status depending upon the parent’s education, occupation and income according to Modified Kuppuswami Classification. (6)

2. Mother was considered a vegetarian if she consumed milk but not eggs.

3. Exclusive breast-feeding was defined as a child who had received breast milk only for the first 6 months of life.

4. Developmental Delay was said to be present if the child showed significant backwardness in any one of the four domains of development while regression of milestones was said to be present if the child lost any of the milestones previously learnt.

5. Nutritional status of each child was assessed according to IAP classification of malnutrition. 6. Signs of Iron deficiency were said to be present

if the child showed nail changes like koilonychias, spoon shaped nails, platynychia, and brittle nails.(1)

7. Hyperpigmentation of nail beds and knuckles, glossitis, angular stomatitis, and bald tongue were considered features of vitamin B12

deficiency. (3,5)

8. Each child was classified depending upon his haemoglobin level into:-(9)Mild anemia:- 9-11 gms/dl,Moderate anaemia:-7-9 gms/dl,Severe anaemia:-5- 7 gms/dl,Very Severe anaemia < 5 gms/dl (7)

9. Microcytosis was defined as MCV < 80 flemtolitre, Macrocytosis as MCV above 95 flemtolitre, Normocytic anaemia as MCV between 80-95 flemtolitre.(7)

10. The acceptable reference value for serum B12

was considered to be between 211-911 pg/ml (8)

Vitamin B 12: Chemistry Vitamin B12 is also

known as cyanocobalamin. The predominant physiological form of cobalamin in serum is methylcobalamin and in cytosol as

adenosylcobalamin (9).In the developing world, the deficiency is very widespread, especially in nutritionally challenged pediatric populations in Africa, India, and South and Central America where it is seen mainly in the age group between 3-18 months in association with maternal deficiencies and prolonged breast feeding. This is due to low intakes of animal products, particularly among the poor. B12 deficiency is common among vegetarians

and vegans who do not take B12 supplements. (10)

Normally, approximately 1 mg of vitamin B12 is

stored in the liver, a quantity equivalent to the daily metabolic requirement for 2000 days. Thus, when the dietary supply of vitamin B12 is interrupted or

mechanisms of absorption is impaired, vitamin B12

deficiency does not become evident for 5 years or more.(9) B12 is required in coenzyme form for more

than 121 different enzyme systems. Sources of Vitamin B12: Food Vitamin B12 is naturally found

in animal products, including fish, meat, poultry, eggs, milk, and milk products. Vitamin B12 is

generally not present in plant foods, but fortified breakfast cereals are a readily available source of vitamin B12..(11) Human milk contains 0.0008 mcg-

0.45 mcg of vitamin B12 and 0.29-0.45 mcg of iron

per 100 ml, while cow’s milk contains 0.07-1.15 mcg of vitamin B12 and 0.01-0.38 mcg of iron.

(12)Daily requirement to-maintain stores would be 2 to 5 mcg. Groups at Risk of Vitamin B12

Deficiency Pregnant and lactating women who follow strict vegetarian diets and their infants:

Vitamin B12 crosses the placenta during pregnancy

and is present in breast milk. Exclusively breastfed infants of women who consume no animal products may have very limited reserves of vitamin B12 and

can develop vitamin B12 deficiency within months

of birth. Undetected and untreated vitamin B12

deficiency in infants can result in severe and permanent neurological damage. The American Dietetic Association recommends supplemental vitamin B12 for vegans and lacto-ovo vegetarians

during both pregnancy and lactation to ensure that enough vitamin B12 is transferred to the foetus and

infant. Vegetarians, Older adults, Individuals with pernicious anemia, Individuals who have had gastrointestinal surgery, are at a higher risk of developing Vitamin B 12 deficiency. Clinical Manifestations (5) Vitamin B12 deficiency is

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vitamin B12 deficiency can occur without anemia, so

early diagnosis and intervention is important to avoid irreversible damage.(14) Vitamin B12

deficiency has been known to result in a demyelinating disorder of the central nervous system called subacute combined degeneration of the spinal card. which causes burning pain or loss of sensation in the extremities, weakness, spasticity and paralysis of lower limbs, confusion, disorientation, and dementia. (9) Hematologic features (5) The hematological effects of Vitamin B12 deficiency are indistinguishable from those of

folate deficiency.

Peripheral blood:

Anaemia with a low reticulocyte count,Macrocytosis with MCVs are in the range of 110-130 fl,Dyserythropoeitic features - a variety of red cell inclusions are seen including basophilic stippling, Howell Jolly bodies, Cabot rings, polychro-matophilia, and nucleated red cells,Nuclear hypersegmentation of polymorphonuclear leucocytes.and thrombocytopenia of a mild to moderate degree may be present.

Bone marrow:

Hypercellularity especially the erythroid compartment with the myeloid:erythroid ratio changing from 3:1 to about 1:1.,megaloblastic erythropoiesis,abnormal leucopoiesis with giant metamyelocytes and band cells, megakaryocytes with hypersegmentation. and giant platelets

Biochemical abnormalities:

Serum homocysteine (HCYS) and serum methylmalonic acid (MMA) levels done together are useful in diagnosing and differentiating between Cobalamin and folate deficiency. In Cobalamin deficiency levels of both are significantly elevated, whereas with folate deficiency, only HCYS is raised with normal levels of MMA.

Serum Cobalamin and serum folate levels are more easily available tests, however both are subject to fallacies of false positivity and negativity. If cobalamin malabsorption is suspected, serum IF antibodies and the Schilling test is done to confirm juvenile pernicious anaemia and/or understand the mechanism of malabsorption.

RESULT AND DISCUSSION

During the study 100 infants in the age group of 3-6 months had been examined and investigated in the Well Baby Clinic for vitamin B12 deficiency and

anemia. Among the 100 infants 53 were male and 47 were female. Among the 53 male infants 46 were having anemia and 29 is found to have vitamin B12

deficiency, while among 47 female 36 were having

anemia 26 are deficient for vitamin B12. Presence of anemia among different age group: All over 82% of infants were found anaemic among 3-6 months age group. These infants came for Well Baby Clinic follow up and they did not have any complaints including infants with moderate and severe anaemia.NFHS-3 survey shows that the incidence of anemia in children aged 6-35 months is 79.2% with 72.7% in urban areas and 81.2% in rural areas.(4)

Table 1: Haemoglobin level and vitamin B12

deficiency

Hb level Vit B12 defi.(+) Vit B12defi.(-) Total

<=11 50(60.2%) 33 83

> 11 5(29.4%) 12 17

Total 55 45 100

When chi square test was applied to the above table to determine whether vitamin B12 deficiency have

any association with the haemoglobin level of the child, it was found that the results were statistically significant(p=0.0199). It was enlightening to see that 5 infants without anaemia had associated Vitamin B12 deficiency. So vitamin B12 deficiency

can be present in children without anaemia.

Table 2: Age group and vitamin B12 deficiency

Age group

Vit B12

defi.-present

Vit B12

defi.-absent

Total

3 month 27(53%) 24 51

4 month 19(53%) 17 36

5 month 09(69%) 04 13

Total 55 45 100

Above data shows that prevalence of Vitamin B12

deficiency increases as the age group advances. But as this study sample is small, it needs to be evaluated on a large study group before considering it as significant. When chi square test was applied to the above table to determine whether age group of child have any bearing with the vitamin B12

deficiency ,it was found that the results are not statistically significant(p=0.542).Majority of the children, almost 85% belonged to the lower socioeconomic strata. This is because the majority of patients included in our study were from poor families, as this study was conducted in a government hospital. In a study conducted by Miriam Aracely, at University of California, Davis in 2007 for prevalence of vitamin B12 deficiency

among 127 infant, it was found that the prevalence of vitamin B12 depletion was more among lower

SES group and lower dietary intake of vitamin.(15)

Table 3: Mother’s diet and vitamin B12 deficiency

Mother’s diet Vit B12 defi.(+) Vit B12defi.(-) Total

Vegetarian 20(69%) 9 29

Nonvegetarian 35(49.3%) 36 71

Total 55 45 100

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significant. Odds ratio revealed that chances of developing B12 deficiency in children with

vegetarian mothers is 2.3 times higher than those compared with non vegetarian mother. In a study conducted by Kankonkar et al, it was found that B12

deficiency was found in 43.7% of the vegetarians as compared to non vegetarians in whom the B12

deficiency was found in 13.04%. Thus there was significant relationship between the prevalence of B12 deficiency and vegetarian diet. Muslims, mostly

non vegetarians were found to have a small number of serum vitamin B12 deficient patients. The reason

for the increased occurrence of vitamin B12

deficiency among vegetarians is because this vitamin is only present in foods of animal origin like egg, meat, fish and milk. Milk is a good source of vitamin B12 for the vegetarians. (16)

Table 4: MCV and Vitamin B12 deficiency

MCV Vit. B12 defi.(+) Vit. B12 defi(-) Total

Microcytic 44(54.3%) 37 81

Normocytic 0(53%) 08 17

Macrocytic 2(100%) 0 2

Total 55 45 100

In our study, it was found that, among the 55 infants deficient for vitamin B12, 44 of them had microcytic

RBCs, 9 had normocytic RBCs and 2 had macrocytic RBCs. So, though the infants are deficient for vitamin B12, they have associated

micocytic anaemia. Above table shows that Vitamin B12 deficiency can exist with microcytic and

normocytic anaemia also.

Table 5: Clinically pallor and Vitamin B12

deficiency

Pallor Vit. B12 defi.(+) Vit. B12 defi.(-) Total

Some 36(61%) 23 59

No pallor 19(46.3%) 22 41

Total 55 45 100

In our study, it was observed that clinically pallor was present in 59 infants and 36(61%) were having associated vitamin B12 deficiency. While among the

infants having no pallor clinically, 19(46.3%) were deficient for vitamin B12. Among the 100 infants, 41

infants have clinically no pallor but 19(46.3%) of them have associated vitamin B12 deficiency.

Among the 100 infants 6 have received vitamin supplementation in form of multivitamin drops, 4 infants had taken it for 1 month and 2 infants had for 2 months. Out of these 6 infants, 2 are deficient for vitamin B12. Details of supplements and

composition and dose could not be analysed as mothers did not recall details. None of infant had other clinical features apart from pallor. Developmental delay and regression of milestones was not observed.

CONCLUSION

1. Almost 82% of infants have anaemia (Hb<11) 2. 55(55%) infants were found to have vitamin

B12 deficiency

3. Vitamin B12 deficiency can present in children

without anaemia.

4. Children of Vegetarian mothers were having 2.3 times more chances of developing B12

deficiency. The axis of maternal malnutrition, vegetarian mother, and prolonged exclusive breast feeding predisposes to the development of Vitamin B12 deficiency. Milk is a good

source of Vitamin B12 among the vegetarians. It

is thus recommended that all strict vegetarian mothers should be advised to take milk during pregnancy and lactation to prevent vitamin B12

deficiency in the offspring.

5. Vitamin B12 deficiency can exist with

microcytic, normocytic or macrocytic anaemia.

6. Association of low birth weight and small for gestational age infants with vitamin B12

deficiency needs to be evaluated on a larger sample size for its significance with vitamin B12 deficiency.

Recommendation: Early supplementation of vitamin B12 during infancy is recommended. There

is a need to stress about the intake of balanced food (vegetarian mothers to consume milk) during pregnancy and in lactation to prevent vitamin B12

deficiency in the offspring. The limitation of the Study: Larger sample size and an even distribution of the sample need to be made to generalize the findings to the entire population. Maternal B12 levels

should simultaneously be evaluated to confirm B12

deficiency in the mother. Clinical features of Folate deficiency are also similar to those of B 12 deficiencyand therefore folate levels should have been estimated.Due to logistic reasons , biochemical tests to rule out iron deficiency and folate deficiency were not done

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