B12 and Folate Deficiency - Lady Hardinge Medical College Supplementary Info

8/8/2019 B12 and Folate Deficiency - Lady Hardinge Medical College Supplementary Info

1/10

Supplementary Information Submitted to the SCN Working Group

on Micronutrients Report 2006

Vitamin B12 and folate deficiency: megaloblastic anemia and

beyond Dr Jagdish Chandra, MD, FIAPProf. of Pediatrics,

Lady hardinge Medical College, andKalawati Saran Childrens Hospital

New Delhi.

Deficiency of vitamin B12 and folate most commonly results in megaloblastic anemia

(MA). Other less common manifestations resulting from deficiency of thesehematopoeitic micronutrients in children include neuro-developmental effects and

abnormal movements. Neural tube defects result from deficiency in mothers during

pregnancy. Bone loss resulting in osteopenia, osteoporosis and pathological fractures

and cardiovascular effects predisposing to coronary artery disease are observed inadults and elderly patients (1,2).

Megaloblastic anemia (MA) is a distinct type of anemia characterized by macrocyticRBCs and typical morphological changes in RBC precursors. The precursors are

larger than the cells of same stage and maturation and exhibit disparity in nuclear-

cytoplasmic maturation. Basic underlying pathogenetic mechanism in MA isdeficiency of folic acid (FA) and/or vitamin B12 at the cellular level with resultant

impairment of DNA synthesis.

This article reviews the certain important aspects of MA and other effects of

deficiency of vitamin B12 and folate.

Prevalence of MA is on the rise ?

Answer to this question may not be forthcoming easily as varying criteria have beenused in literature to point towards anemia resulting from deficiency of FA or vit B 12.Some studies have considered macrocytosis of red cells as indicative of this type of

anemia while others have defined MA by presence of megaloblastic changes in the

bone marrow. Still others have used subnormal micronutrient levels to define thistype of anemia. Table I shows the proportion of cases contributed by macrocytic/

anemia/MA/ FA- vit. B12 deficiency as observed in various series on nutritional

anemia in children or during survey of micronutrient deficiency.While proportion of

these cases seems to be increasing over the years, of particular interest is theobservation by Gera et al which shows an almost four fold rise in proportion of

macrocytic anemia cases over less than a decade at one center-2 % in 1991 and 7.8%

in 1999 (Table I). A recent report shows 46.9% of non-anemic adult subjects havingsubnormal levels of B12 or folate- B12 deficiency being five times more common than

folate.(10)

Further, the timing of the reports reveals a renewed interest in the subject over last10-15 years. Observations on adults and children from other developing countries

including Pakistan, Zimbabve, Mexico and Guatemala during this period shows that

the trend in India may be reflecting a more generalized phenomenon (11-14). Theincrease in prevalence of MA is also supported by observation that MA accounts for


2/10

maximum/ a large number of cases of pancytopenia in many Indian series (see details

below(15-18) .

Table I : Prevalence of MA, macrocytic anemia or B12 /folate deficiency

No and Series Year Proportion of cases

1. Ghai et al(3) 1956 19.1%

2. Dalal et al (4) 1969 18.0%

3. Ghai et al (5) 1977 02.0%

4. Sharma et al(6) 1985 24.0%

5. Gomber et al (7) 1998 42.1%

6. Chaudhry et al (8) 2001 27.1%

7.Gera et al (9) 19911999

02.0%07.8%

Table II: Relative prevalence of vitamin B12 and folate deficiency

Indian Series: Year / Country Population/

Study group

Fola

te

Def.(%)

B12

def.

(%)

Combined

deficiency

(%)

Bhende et al (19) 1965 Nutr. MA 54.9 7.0 5.3

Mittal et al (20) 1969 MA, child 57.1 22.4 10.2

Sarode et al (15) 1989 MA, all ages 6.8 76.4 8.8

Gomber et al(21) 1998 MA, children 10.0 50.0 20

Gomber et al (7) 1998 Preschool 2.2 36.6 2.2

Chaudhry MW(8) 2001 Anemic child 12.0 19.0 14.0

Chandra et al (22) 2002 MA, children 20.0 32.0 20.0

Khanduri et al(10) 2005 Gen. Population 6.8 33.0 8.3

Other countries

Mukibi et al (12) 1992,Zimbabwe

MA, all ages 17.0 51.0 32.0

Maddood-ul-

Mannan et al (11)

1995, Pakistan MA, all ages 8.0 56.0 20.0

Allen et al (14) 1995, Mexico Gen. population - 19-41 -

Casterline etal (13) 1997,

Guatemala

Lactating 9.0* 46.7* -

Garcia-Casal et al 2005, Gen. Population 30.0 11.4 -


3/10

(23) Venezuala Pregnancy 36.3 61.3 -

*Includes deficienct and low levels of folate and cobalamin

Relative prevalence of deficiency -B12 / Folate:

Deficiency of B12 or folate can not be differentiated easily from one another as theclinical and hematological features resulting from the deficiency of bothmicrnutrients are similar. Estimation of serum levels are required to be certain of

the deficient micronutrient. Serum B12 and folate assay used to be cumbersome

dependent upon biological methods , hence they were not performed widely.

Currently most widely used methods is radioimmunoassay which because of itshigh cost is not routinely available in developing countries. HPLC based assay

have also become available. The problem is further compounded by the wide

range over which the levels are obtained in normal individuals and normal valuesobtained in patients with frank megaloblastic morphology and severe anemia.

Combined deficiency is also seen in many cases (24).

TableII shows the proportion of cases according to micronutrient deficiency (thestudies have not been differentiated whether they are on cases with megaloblastic

anemia or population based studies as the proportions are under comparison). The

Indian series from 1965 shows that isolated B12 or combined deficiency was

present in nearly 5% and 60 % instances while folate deficiency accounted fornearly 80% (19)However, Sarode et al from PGIMER Chandigarh, reported B12

deficiency in nearly 85 % cases with megaloblastic anemia ( adults included, 15)

The later studies from Delhi/ New Delhi have also highlighted that B12 deficiencyis far more common than folate deficiency. A study from our hospital on cases

with nutritional anemia shows B12 deficiency in 19 % cases and folate deficiency

in 12 %. In addition nearly 35 % cases had levels of B12 which could be classified

as low (8).

Higher prevalence of B12 deficiency among population groups and cases with MA fromIndia also reflects a more widespread trend. A study from Mexico showed B12

deficiency in 19% -41% of various population subgroups while no cases with folate

deficiency were observed(14). Another study on Guatemalan lactating mothers

revealed B12 deficiency in 46% compared to 9% prevalence of folate deficiency (13)Series on MA patients from Pakistan and Zimbabve revealed B12 deficiency in over

50% cases while folate deficiency was seen in only 8% and 17 % cases respectively

(11,12). Considering the fact that most common cause of B12 deficiency in youngchildren is the maternal deficiency leading to decreased stores at birth and its

consequences, these studies including adults may have a direct relevance to pediatric

population.

Etiology of MA/B12-folate deficiency:

In India and other developing countries, most cases of MA are caused by nutritional

deficiency of folate, B12 or both. Pernicious anemia due to intrinsic factor deficiency,

malabsorption resulting in folate deficiency (celiac disease) and certain inborn errorsof metabolism eg. mthylmalonic aciduria (B12 deficiency) and methylene

tetrahydrofolate reductase deficiency (folate) account for minority of cases.


4/10

Nutritional deficiency is far more common in vegetarian than in non-vegetarian

families (24,25). B12 deficiency seen in infants and young children has been

particularly related to maternal deficiency which results in poor body stores at thetime of birth. These underprivileged infants who are exclusively/ predominantly

breastfed for prolonged period (in some instances as much as 3-5 years) tend to

develop B12 deficiency as the breast milk content of B12 in these mothers is far belownormal ( poverty- vegetarianism-exclusive prolonged breast feeding axis). Cobalamin

content of breast milk is lower in vegetarian mothers and is positively correlated with

their serum cobalamine levels (13,26). We have documented a good co-relationbetween serum levels of the mothers and their suckling infants and young children

(22). From the developed countries, cases of MA are being reported among infants

born to vegetarian mothers (25,27).

Increasing B12 and folate deficiency is not entirely related to poverty. Biochemicalevidence of recent B12 malabsorption has been documented in some populations.

Giardia infection, particularly acquired in Asian countries has been demonstrated to

cause folate malabsorption. H.pylori infection has been incriminated to cause B12

malabsorption among adults (14).

Clinico-hematological profile: Anemia and Beyond:

Most cases of MA are seen in poor vegetarian families. Infants and young children

who are not adequately weaned are particularly susceptible. Hence most cases tend

to be moderately or severely malnourished. Anemia, anorexia, irritability, easy

fatigability are clinical features common to other causes of anemia.Clinical features peculiar to MA include hyperpigmentation of knuckles and

terminal phalanges (observed in Asian communities), enlargement of liver and

spleen (seen in upto30-40% cases). Petechial and other hemorrhagic manifestationshave been reported in upto 25% cases. Presence of bleeding with severe anemia

makes them clinically indistinguishable from aplastic anemia. Cases with MA may

mimic acute leukemia due to presence of hepatosplenomegaly (19,21,22,28).Tremors have been described to occur as a distinct entity in children of north and

central India The Infantile Tremors Syndrome (29,30) . These cases mostly have

macrocytic anemia and developmental regression in addition to tremors. Cases ofMA not presenting with tremors also exhibit developmental retardation/ regression

in association with severe anemia. Recently a group of infants has been described

having microcephaly and developmental retardation even before anemia became

clinically evident. Occurrence of abnormal movements in association withhypotonia, psychomotor retardation, apathy and failure to thrive is being reported in

western literature as well (31,32). These cases have been shown to have diffuse

frontotemporoparietal cortical atrophy on MRI of brain (25,32). Some studies reportpersistence of neurological consequences even after treatment (33). Impairment of

cognitive function is also described in children and adolescents with B12 deficiency

even in absence of anemia (34).

Laboratory Findings :

Laboratory investigations reveal macrocytic normochromic RBCs. On the

electronic cell counter, MCV is increased and RBC count is decreased

proportionate to degree of anemia. Nucleated red cell precursors may be seen and


5/10

they show megaloblastic changes. In the WBC series, hypersegmentation of

neutrophils has been described as an early feature of folate-B12 deficiency. In

addition, neutropenia is seen in 17- 49 % cases in various series. Similarly, plateletcounts are decreased observed in as many as 44-80 % cases. It is thus not

surprising that the cases with MA manifest with pancytopenia and mimic aplastic

anemia (15,21,22,28). From India, in various series of patients presenting withpancytopenia, MA has been found to be more common cause compared to aplastic

anemia and acute leukemia. Sarode et al were among the first to report this

observation in patients of all age group from a referral hospital (15). In anotherseries from a referral hospital, MA accounted for 22.28% cases of pancytopenia

seen over 6 years. This was second only to aplastic anemia (18). Khunger et al have

observed MA accounting for over 72% cases (all age groups) with pancytopenia

(17). In our series of 109 patients of pediatric age group presenting withpancytopenia, MA was the single most common cause (28.4%). Aplastic anemia

and acute leukemia accounted for 20% and 21% cases respectively (16).

Increased levels of homocysteine have been documented in folate- B 12 deficiency

and are being linked to coronary artery disease.

Diagnosis and Differential Diagnosis:

Other causes of macrocytosis should be considered in the differential diagnosis of

MA. These causes include aplastic anemia and other marrow failure syndromes

(pure red cell aplasia, transient erythroblastopenia of childhood etc particularly

during recovery phase), congenital dyserythropoietic anemia, cold agglutinindisease, chronic liver disease and hypothyroidism. These conditions are obviously

less frequent and have only mild to moderate macrocytosis ( higher the MCV, more

are the chances that the case will be of MA). Presence of anisocytosis, macro-ovalocytes and tear drp cells are most prominent in MA and help differentiating it

from other causes of macrocytic anemias (35). Red cell distribution width (RDW)

which is an indicator of anisocytosis has been found to be significantly higher incases with MA as compared to aplastic anemia (36). However Saxena et al have

reported normal RDW in 31% cases with pernicious anemia. In cases with

increased RDW, a progressive fall was noted during recovery with treatment. Somecases showed an initial increase before a fall in RDW was observed (37).

Diagnosis rests on demonstration of megaloblastic changes in the circulating red

cells precursors or bone marrow aspiration.

Levels of folate and B12 are required to identify the deficient micronutrient. Cut offlevels of 100-150 pg/ml of B12 and 3-5 ng/ml of folate have been used to define

respective deficiency states (21,22). Serum levels of homocystiene are increased in

deficiency of folate and B12 but levels of methylmalonic acid (MMA) are increasedin B12 deficiency only ( even increased urinary levels of MMA are considered

diagnostic of B12 deficiency). Very high specificity of methyl-malonicaciduria in

B12 deficiency has recently been confirmed. The authors also observed highspecificity of FIGLU test in folate deficiency. The authors advocated for using these

relatively inexpensive tests for diagnosis of B12 and folate deficiency (13,38). This

assumes significance in light of the fact that levels of B12 and folate are quite


6/10

variable, difficult to measure and influenced by even subclinical hepatic

dysfunction.

Levels of lactate dehydrogenase (LDH) have been reported to be elevated in MA. Ina recent Indian study, levels above 3000 IU/l were found to be diagnostic of MA.

Reverse isoenzyme pattern (LDH1 > LDH2) was found to be a good adjuvant in the

differential diagnosis of MA from hemolytic anemia. (39)Schilling test and its modifications are required in cases where the diagnosis of

pernicious anemia is in question.

Treatment :

Like any other deficiency state replacement therapy is required. Anemia and other

cytopenias respond to administration of very small doses of drugs. However, since

folate is available as a 5 mg tablet and its over dose is not associated with adverse

effects, 5 mg daily dose has been used.For B12 deficiency, parenteral administration of B12 is usually recommended.

Intramuscular 1mg dose has been traditionally used but with this high dose cases

have developed tremors and other extrapyramidal symptoms (31). We observed

development of tremors in 6 out of 51 cases within few hours of administration of 1mg dose. However, these tremors and other neurological signs have been self-

limiting but their appearance may influence the compliance. Sudden increase in thelevels of neurotransmitters has been offered as the plausible explanation for this

neurological phenomenon (24,31) Currently we are using a dose of 250 g in

infants and 500 g in older children.The duration of treatment is not as standardized as in case of iron deficiency

anemia. Six to eight weeks treatment is usually described as sufficient. Decrease in

MCV, reticulocytosis, and improvement in platelet and neutrophil counts are

observed within few days. In our follow up, some cases have developedthrombocytosis which resulted in stroke in one patient. Hence careful monitoring of

blood counts is required during treatment.B12 and folate deficiency in adults/ elderly:Levels of both -B12 and folate have been shown to decrease with age. In elderly, this

fall may lead to precarious levels. The low levels may in turn lead to vasculotoxic

hyperhomocysteinemia(1,2). As homocysteine levels increase with deficiency ofeither nutrient, tackling of deficiency of both micronutrients is being advocated.

Some recent work suggests that vasculotoxic effect of folate may be independent of

homocysteine levels (2).

Brittleness of bones in elderly due to decreased bone mineral density (BMD) isincreasingly being reported in adults with folate and/or B12 deficiency. Initial

reports suggested that this effect also could be due to increased levels of

homocysteine, but recent data suggests a more direct action independent ofhomocysteine levels (40).

Conclusions:

It is very obvious that there is resurgence of articles on folate-B12 deficiency/MAover the last 10-15 years. This clearly reflects renewed interest in the subject as

more and more cases are being seen in clinical practice. The phenomenon appears

to be widespread. Many developing countries eg. India have anemia control/prophylaxis programs and in addition there is overall improvement in general


7/10

standard of living. In light of these facts, the causes for increased incidence of

folate-B12 deficiency and /or MA needs to be elucidated. As pointed out earlier,

over the last few years, B12 deficiency has taken over as more commonmicronutrient deficiency as compared to folate. Even this shift needs to be

explained. Role of malabsorption particularly giardiasis and H. pylori needs to be

clearly understood.

REFERENCES:

1. Cagnacci A, Cannoletta M, Baldassari F, Volpe A. Low

vitamin B12 and bone loss: A role for folate deficiency. JClin Endocrinol Metabol 2004; 89:4770-4771.

2. Doshi SN, McDowell IFW, Moat SJ, Payne N, Durrant HJ.

Lewis MJ, Goodfellow J. Folic acid improves endothelial

function in coronary artery disease via mechanisms largelyindependent of homocysteine lowering. Circulation

2002;105: 22-26.3. Ghai OP . Aetiology of anemias in infancy and childhood

(in New Delhi) Indian J Child health 1956, 95-100.

4. Dalal RJ, Udani PM, Parekh JG Megaloblastic anemia in

infancy and childhood. Indian Pediatr 1969, 6:255-262.5. Ghai OP, Choudhry VP, Singla PN et al. Nutritional macrocytic anemia

in infancy and childhood. In Ghai OP.New Developments in Pediatric

Research, Interprint, New Delhi,1977,pp121.6. Sharma A, Sharma SK, Grover AK et al. Anemia in protein energy

malnutrition. Indian Pediatr 1985;22;841-844.

7. Gomber S,Kumar S, Rusia U et al. Prevalence and etiology of

nutritional anemias in early childhood in an urban slum. Indian J MedResearch 1998, 107: 269-273.

8. Chaudhary MW. Clinico- hematological study of nutritional anemia in

young children Thesis for MD Pediatrics, Delhi University, 2001.9. Gera R, Singh ZN, Chaudhury P. Profile of nutritional anemia in

hospitalized children over a decade. Conference Abstracts, 38 th National

conference of Indian academy of Pediatrics Patna 2001, HO-09, pp 60.10. Khanduri U, Sharma A, Joshi A. Occult cobalamin and folate

deficiency in Indians. Natl Med J India 2005; 18: 182-183.

11. Madood-ul-Mannan, Anwar M, Saleem M etal.Study of serum vitamin

B12 and folate levels in patients of megaloblastic anemia in northern

Pakistan. J Pak Med Assoc 1995, 45:187-188.12. Mukibi JM, Makumbi FA, Gwanzura C. Megaloblastic anemia in

Zimbabwe: spectrum of clinical and hematological manifestations. EastAfr Med J 1992,^9: 83-87.

13. Casterline JE, Allen LH, Ruel MT. Vitamin B12 deficiency is very

prevalent in lactating Guatemalan women and their infants at three monthspostpartum. J Nutr1997, 127:1966-1972.


8/10

14. Allen LH, Rosado JL, Casterline JE et al. VitaminbB 12 deficiency and

malabsorption are highly prevalent in Mexican communities. Amer J Clin

Nutr 1995; 65:1013-1019.15. Sarode R, Garewal G, Marwaha N et al. Pancytopenia in nutritional

megaloblastic anemia: A study from north-west India. Trop Geog Med

1989;41:331-33616.Bhatnagar S, Chandra J, Narain S et al. Pancytopenia in children

Etiological profile. J Trop Pediatr 2005;51: 296-299.

17. Khunger JM, Arulselvi S, Sharma U, Ranga S, Talib VH.Pancytopenia- a clinicohematological study of 200 cases.

Indian J Pathol Microbiol 2002; 45: 375-379.

18. Kumar R, Kalra SP, Kumar H, Anand AC, Madan H.

Pancytopenia- a six year study. J Assoc Physicians India2001; 49: 1078-1081.

19. Bhende YM. Some experience with nutritional megaloblastic anemia.

J Postgrad Medicine, 1965;11:145-155.

20. Mittal VS, Agarwal KN. Observations on nutritional megaloblasticanemia in early childhood. Ind J Med Research ,1969,57:730-738.

21. Gomber S, Kela K, Dhingra N. Clinico-hematological profile ofmegaloblastic anemia Indian Pediatr 1998;35:54-57.

22. Chandra J, Jain V, Narain S et al. Folate and cobalamin deficiency in

megaloblastic anemia in children. Indian pediatr 2002, 39: 453-457.

23. Garcia-Casal MN, Osorio C, Landaeta M, Leets I, matus P,Fazzino F, Marcos E. High prevalence of folic acid and

vitamin B12 deficiencies in infants, children, adolescents

and pregnant women in Venezuela. Eur J Clin Nutr 2005;59: 1064-1070.

24. Jain V.Clinico-hematological study of megaloblastic anemia. Thesis

for MD ( Pediatrics) Delhi University, 1999.25. SmolkaV, Bekarek V, Hlidkova E. et al. Metabolic

complications and neurologic manifestations of vitamin B12deficiency in children of vegetarian mothers. Cas Lek Cesk2001; 140: 732-735.

26. Specker BL, Black A, Allen L et al. Vitamin B12 : Low milk

concentration are related to low serum concentrations in

vegetarian women and methylmalonic aciduria in theirinfants. Amer J Clin Nutr.1990; 52: 1073-1076

27. McPhee AJ, Davidson GP, Lealy M, Beare T. Vitamin B12deficiency in a breast fed infant. Arch Dis Childh 1988; 63:921-923.

28. Marwaha RK, Singh S, Garewal G et al. Bleeding

manifestations in megaloblastic anemia. Indian J Pediatr1989;56:243-247.

29. Garewal G, Infantile tremor syndrome: a vitamin B12deficiency syndrome in children. J Trop Pediatr

1988;34:174-178


9/10

30. Jadhav M, Webb JKB, Vaishnava S, Baker SJ. Vitamin B12deficiency in Indian infants: a clinical syndrome. Lancet

1962; ii;903-908.31. Grattan Smith PJ, Wilcken B, Procopis PG et al. The

neurological syndrome of cobalamin deficiency:

Developmental regression and involuntary movements.Movement Disorders,1997;32:39-46

32. Avci Z, Turul T, Unal I. Involunatary movements and

magnetic resonance imaging findings in infantilecobalamin(vitamin B12 ) deficiency. Pediatrics 2003; 103:

684-686.

33. von Schenck U, Bender-Gotze C, Koletzko B. Persistence

of neurological damage induced by dietary vitamin B12deficiency in infancy. Arch Dis Child 1997; 77: 137-139.

34. Louwman MWJ, van Dusseldorp M, van de Vijver FJR, et

al. Signs of impaired cognitive function in adolescents with

marginal cobalamin status. Am J Clin Nutr 2000; 72: 762-769.

35. Savage DG, Ogundipe A, Allen RH, Stabler SP,Lindenbaun J. Etiology and diagnostic evaluation of

macrocytosis. Am J Med Sci 2000; 319: 343-352.

36. Gupta PK, Saxena R, Karan AS, Choudhury VP. Red cell

indices for distinguishing macrocytosis of aplastic anemiaand megaloblastic anemia. Indian J Pathol Microbiol 2003;

46: 375-377.

37. Saxena S, Weiner JM, Carmel R. Red cell distributionwidth in untreated pernicious anemia. Am J Clin Pathol

1988; 89:660-663.

38. Marin GH, Tentoni J, Cicchetti G. Megaloblastic anemia:rapid and economical study. Sangre (Barc) 1997; 42: 235-

238.

39. Jaswal TS, Mehta HC, Gupta V, Singh M, Singh S. Serumlactate dehydrogenase in diagnosis of megaloblastic

anemia. Indian J Pathol Mictobiol 2000; 43: 325-329.

40. MaFarlane SI, MUniappa R, Shin JJ, Bahtiyar G, Sowers

JR. Osteoporosis and cardiovascular disease: brittle bonesand boned arteries, is there a link? Endocrine 2004; 23:1-

10.


10/10

B12 and Folate Deficiency - Lady Hardinge Medical College Supplementary Info

Documents

Transcript of B12 and Folate Deficiency - Lady Hardinge Medical College Supplementary Info