2. Folate & Function
• The ord folate is deri ed fro the Lati root foliu = Leaf
• Folate is important in DNA and methylation cycles, and red blood
cell formation
3. Deficiencies
• Folate losses via excretion from the urine, skin and bile.
• Resulting in anemia, leucopenia, and thrombocytopenia.
• Reduction in cell division in the lining in the gut – prone to infection,
secondary malabsorption.
• Elevation in plasma homocysteine – associated with cardiovascular
disease.
4. Symptoms & Deficiencies
• Symptoms: Weakness, fatigue, difficulty in concentrating, irritability,
headache, palpitations, and shortness of breath.
• Folate deficiency during pregnancy can results in neural tube defects
e.g. spina bifida, anencephaly, encephalocele
5. Food sources
• Abundant in green leafy vegetables, legumes.
• >3 servings per day of green leafy vege
• Fortified food with folate such as bread, oat etc.
Bioavailability
• In natural food – reduced as much as 25-30%.
• Affected by the removal of the polyglutamate chain by the intestinal
conjugase.
• Synthetic folic acid – approximately 100%
6.
7.
8.
9.
10. Dietary Folate Equivalents
• Folic acid recommendation is expressed as dietary folate equivalents
(DFE)
• Differences in the absorption of food folate, synthetic folic acid from
supplements and food fortified with folic acid.
• Supplements – 100% bioavailable.
• Food fortified (folic acid consumed with natural food)– 85%
bioavailable.
• Natural food folate, estimation from study by Sauberlich et al. (1987),
- 50% bioavailable.
11. • 1 µg of DFE = 1.0µg food folate
= 0.6 µg folic acid added to foods
= 0.5 µg folic acid taken without food
• 1 µg folic acid as a fortificant = 1.7µg DFE
• 1 µg folic acid as a supplement, fasting = 2.0µg DFE
Dietary Folate Equivalents
12. Interaction with nutrients and drugs
• Certain fiber e.g. wheat bran may decrease the bioavailability of
certain forms of folate
• Alcohol intake impaired intestinal folate absorption and hepatobiliary
metabolism and increasing renal folate excretion.
• Medications such as nonstreroidal anti-inflammatory,
anticonvulsants, methotrexate and oral contraceptive agents may
exert antifolate activity.
13. Function
Age Recommendation Age Tolerable Upper Level
0-5 months 80 µg/day DFE Not possible to establish
6-11 months 80 µg/day DFE
1-3 years 160 µg/day DFE 1-3 years 300 µg/day DFE
4-6 years 200 µg/day DFE 4-8 years 400 µg/day DFE
7-9 years 300 µg/day DFE 9-13 years 600 µg/day DFE
Boys 10-18 years 400 µg/day DFE Adolescents
14-18 years
800 µg/day DFE
Girls 10-18 years 400 µg/day DFE
Men 19-65 years 400 µg/day DFE Adult Men 1000 µg/day DFE
Women 19-65
years
400 µg/day DFE Adult Women 1000 µg/day DFE
Men >65 years 400 µg/day DFE
Women >65 years 400 µg/day DFE
Pregnancy 600 µg/day DFE 14-18 years
≥ 9 years
800 µg/day DFE
1000 µg/day DFE
Lactation 500 µg/day DFE 14-18 years
≥ 9 years
800 µg/day DFE
1000 µg/day DFE
The tolerable upper intake level (UL) as suggested by IOM (1998)
14.
15.
16. Function
Iron in the body exist in four classes:
• Iron containing heme proteins in hemoglobin, myoglobin and
cytochromes – important for oxygen transport and electron transport
• Iron Sulphur enzyme (flavoproteins, heme-flavoproteins) – energy
metabolism
• Iron storage and transport protein (transferrin, lactoferrin, ferritin and
hemosiderin) – iron absorption, transport and storage
• Other iron-containing or activated enzymes (Sulphur, nonheme
enzymes)
17. Food sources
• Two types of iron in foods – haem iron and non-haem iron
• Haem iron – meats, fish, seafood, and poultry (40%)
• Non-haem iron – plant foods: breads, cereals, dark leafy vegetables
(spinach, fern shoots, kangkung), legumes and eggs
18. Deficiencies
• Impair work performance: reduction in tissue oxidative capacity, which
affect endurance and efficiency.
• Decrease in hemoglobin concentration affects work output. (Haas and
Brownlie, 2001)
• Impair performance in tests of mental and motor function in childhood.
It is reversible when iron was given and anemia corrected. (Grantham-
Mcgregor & Ani, 2001)
• Significant problem in pregnancy (IOM, 2001)
• Increase perinatal maternal mortality with severe anemia (hemoglobin <40g/l)
• Two fold risk of maternal death with moderate anemia (hemoglobin <80g/l)
• Heart failure, hemorrhage and infection have been identified as possible causes.
19. • Maternal anemia associated with premature delivery, low birth
weight and increased infant mortality.
• Also li it the i fa t’s iro status
• High haemoglobin concentration at the time of delivery are also
associated with adverse pregnancy outcomes: small for gestational
age.
• Iron deficiency limits the expansion of the maternal erythrocyte cell
mass while elevated hemoglobin level decrease plasma volume –
hypertension and eclampsia.
20. Factors affecting iron requirement
• From Loh & Khor (2010) The prevalence of anaemia being highest among the
Indians (26.4%) and lowest among the Malays (16.4%). The prevalence of IDA
was highest in Indians (18.0%) followed by Chinese (9.9%) and Malays (4.3%).
Intake of iron was the highest for the Indians (16.0 mg/d) and the lowest for the
Chinese (11.3 mg/d).
• Iron status of subject
• Increase absorption when stores are low and decreasing when iron are high.
• Iron stores are first depleted (serum ferritin is lowered), concomitant reduction in
the concentration of Hb
• Types of iron
• Dietary haem iron is better absorbed because haem is soluble at the pH of the small
intestine.
• Non heam iron used for fortification of food is partially absorbed.
• Haem iron can be converted to non-haem iron if foods are cooked at a high
temperature for too long.
21. • Enhancing and inhibiting factors
• Enhancing absorption – ascorbic acid and organic acid; meat chicken, fish and
seafood; fermented vegetables and fermented soy sources
• Inhibiting factors – phytates and inositol phosphates; iron-binding
polyphenols; calcium; soy proteins and vegetables protein
22. Bioavailability
• Determined by: the amount of body stores of iron
• The absorption varies from about 40% during iron deficiency to about 10%
during iron repletion.
• The properties of diet
• The absorption of non-haem iron is depending on the presence of enhancing
or inhibiting factors.
23. Toxicity
• Excess of iron generate reactive oxygen species.
• DNA damage, impaired synthesis of macronutrients, altered cell
proliferation.
• Free iron react with unsaturated fatty acid to form alkoxyl and/or
peroxyl radical, which leading to cell death.
• Play role in carcinogenesis, atherosclerosis, neurodegerative disorders
e.g. Parki so ’s or Alzhei er’s diseases
24. Age % Bioavailability (mg)
10 15
0-5 months Can be met by iron provided through breast milk
6-11 months 9 6
1-3 years 6 4
4-6 years 6 4
7-9 years 9 6
Boys 10-14 years
Boys 15-18 years
15
19
10
12
Girls 10-14 years1
Girls 10-14 years
Girls 15-18 years
14
33
31
9
22
21
Men 19 and above 14 9
Women 19 and above
Premenopause
Postmenopause
14
29
11
9
20
8
Pregnancy 20 20
Lactation 0-12 month
7-12 months2
15
32
10
21
1 Non menstruating
2 lactating women with menstruation
25. Tolerable upper intake levels
• Tolerable upper intake levels (UL)
• Infants and children (0-9 years) 40mg/day
• Adolesce ts a d adults ≥9 years 45mg/day
26. Conclusion
• There are many more studies need to be done to obtained data on
the bioavailability of the nutrients, total intake of the nutrients among
Malaysian, and how diet pattern of Malaysian affect the nutrient
intake.
27. Reference
• Chew, S.C., Loh, S.P. and Khor, G.L, Determination of folate content in commonly consumed Malaysian foods, International Food
Research Journal 19(1): 189-197 (2012)
• Crider, K. S., Yang, T. P., Berry, R. J., & Bailey, L. B. (2012). Folate and DNA Methylation : A Review of Molecular Mechanisms and the
E ide ce for Folate ’ s Role. A erica “ociety for Nutritio , , –38.
• FAO/WHO (2002). Folate and folic acid. In: Human Vitamin and Mineral Requirements. Reorts of a Joint FAO/WHO Expert
Consultation. FAO, Rome; p 53-63
• FAO/WHO (2002). Iron. In: Human vitamin and mineral requirements. Report of a Joint FAO/WHO Expert Consultation. FAO, Rome;
pp 195-221.
• Grantham-McGregor S & Ani C (2001). A review of studies on the effect of iron deficiency on cognitive development in children. J
Nutr 131(2S-2):649S-666S Haas JD & Brownlie T (2001). Iron deficiency and reduced work capacity: a critical review of the research
to determine a causal relationship. J Nutr 131(2S-2): 676S- 688S
• IOM (1998). Folate. In: Dietary References Intakes for Thiamine, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid,
Biotin and Choline. Food and Nutrition Board, Institute of Medicine. National Academy Press, Washington DC; chapter 8, pp 196-305.
• Khor, G. L., Duraisamy, G., Loh, S. P., & Green, T. (2006). Dietary and blood folate status of Malaysian women of childbearing age. Asia
Pacific Journal of Clinical Nutrition, 15(3), 341–9.
• Loh, S. P., & Khor, G. L. (2010). Iron intake and iron deficiency anaemia among young women in Kuala Lumpur. Malaysian Journal of
Medicine and Health Sciences, 6(January), 63–70.
• National Coordinating Committee on Food and Nutrition (NCCFN), Ministry of Health Malaysia. Recommended Nutrient Intakes for
Malaysia. Putrajaya, Ministry of Health Malaysia, 2005
• Sauberlich HE, Kretsch MJ, Skala JH, Johnson HL & Taylor PC (1987). Folate requirement and metabolism in nonpregnant women.
Amer J Clin Nutr 46: 1016-1028
