Significance and sources of folate, foods rich with folate

1. Significance and sources of folate
Domina Petric, MD

2. Significance
• Widely distributed among foods,
particularly those of plant foliar
origin, this abundant vitamin is
underconsumed by people whose
food habits do not emphasize plant
foods.
• It is intimately related in function
with vitamins B12 and B6.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
2

3. Significance
Folate deficiency is an important problem
in many parts of the world, particularly
where there is poverty and malnutrition.
It is an important cause of anemia,
second only to nutritional iron deficiency.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
3

4. Significance
Folate has an important role in the
etiology of homocysteinemia,
cancer and birth defects.
High-level supplements of folate
can mask the macrocytic anemia of
vitamin B12 deficiency, which will
lead to neuropathy if not corrected.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
4

5. Distribution in foods
Folates (folyl polyglutamates)
occur in a wide variety of
foods of both plant and
animal origin.
Liver, mushrooms and green,
leafy vegetables are rich
sources of folate.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
5

6. Dairy products and other
Dairy product Folate μg/100 g
Milk 5-12
Cheese 20
Other
Eggs 70
Brewers´ yeast 1500
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
6

7. Meats
Meat Folate μg/100 g
Beef 5-18
Beef liver 140-1070
Chicken liver 1810
Tuna 15
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
7

8. Cereals
Cereal Folate μg/100 g
Barley 15
Corn 35
Polished rice 15
Unpolished rice 25
Whole wheat 30-55
Wheat bran 80
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
8

9. Vegetables
Vegetable Folate μg/100 g
Asparagus 70-175
Beans 70
Broccoli 180
Brussel sprouts 90-175
Cabbage 15-45
Cauliflower 55-120
Peas 90
Soybeans 360
Spinach 50-190
Tomatoes 5-30
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
9

10. Fruits
Fruit Folate μg/100 g
Apples 5
Bananas 30
Oranges 25
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
10

11. Stability
• Most folates in foods are easily oxidized and
are unstable to oxidation under aerobic
conditions of storage and processing.
• Under such conditions (especially in the
added presence of heat, light and/or metal
ions), FH4 derivatives can readily be oxidized
to the corresponding derivatives of
dihydrofolic acid (FH2) or folic acid, some of
which can react further to yield
physiologically inactive compounds.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
11

12. Stability
Substantial losses in the folate
contents of food can occur as the
result of leaching in cooking
water when boiling: losses of
total folates of 22% for
asparagus and 84% for
cauliflower.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
12

13. Bioavailiability
 Factors that affect the biologic availability of food
folates are:
Antifolates in the diet
Folates can bind to the food matrices. Many foods
contain inhibitors of the intestinal brush border
folate conjugase and/or folate transport.
Inherent characteristics of various folates
Folate vitamers vary in biopotency.
Nutritional status of the host
Deficiencies of iron and vitamin C status are
associated with impaired utilization of dietary folate.
April 19, 2018
Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
13

14. Literature
• Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.
April 19, 2018 14