Significance and sources of folate Domina Petric, MD

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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

Dairy products and other Folate μg/100 g Milk 5-12 Cheese 20 Other Eggs 70 Brewers´ yeast 1500 November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

Meats Meat Folate μg/100 g Beef 5-18 Beef liver 140-1070 Chicken liver 1810 Tuna 15 November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

Cereals Cereal Folate μg/100 g Barley 15 Corn 35 Polished rice Unpolished rice 25 Whole wheat 30-55 Wheat bran 80 November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

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 November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

Fruits Fruit Folate μg/100 g Apples 5 Bananas 30 Oranges 25 November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

Folate vitamers vary in biopotency. 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. November 16, 2018 Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008.

Literature Combs GF. The Vitamins. Fundamental Aspects in Nutrition and Health. Elsevier Inc. 2008. November 16, 2018