Folate:Vitamin B-9

By: Abby Stanley

Overview

Difference between folate and folic acid

Dietary folate equivalents

Sources

RDA and Upper Limits

Overview

Absorption, Transportation and Storage

Functions

Deficiency

Research: Current and Future ApplicationEvidence Analysis

Library

General Information

Water-soluble vitamin

Member of the B-vitamin family

Comes from Latin word “folium”

Formerly known as Folicin

Naturally present in some foods, added to others and available as dietary supplement

Forms coenzyme Tetrahydrofolic acid (THFA)

Folate vs. Folic Acid

Folate

Refers to forms found naturally in foods

Polyglutamate

Folic Acid

Synthetic form, found in supplements and fortified foods

Fully oxidized form of the vitamin

Monoglutamate

Bioavailability

Degree to which the amount of an ingested nutrient is absorbed and is available to the body.

The bioavailability of Folate depends on the source and other factors while taking it in. Dietary Folate vs Synthetic

Folic Acid

Taken with food/fortified food vs On empty stomach

Dietary Folate Equivalents

The RDA for folate is expressed using DFEs. Reflects the higher

bioavailability of folic acid than dietary folate

Example: If Daily Intake is Dietary Folate=100 mcg Folic Acid= 340 mcg

DFE=100 + (340 x 1.7) =100 + 578 =678 mcg

400 mcg DFE

Men

400 mcg DFE

Capable of becoming pregnant should come from both dietary folate and synthetic folic acid

Women

600 mcg DFE

400 mcg from folic acid

200 mcg from dietary folate

Pregnant Women

RDA’s

Sources

Foods

Common Sources Fortified bread and cereal

products Orange juice & citrus fruits Green veggies

Largest Bioavailability Liver Legumes Leafy greens

Dietary Supplements

Stand alone, Multivitamins, prenatal vitamins, and in supplements containing other B-complex vitamins

Sources

Food Processing can destroy 50-90% of available folate!

Folic Acid Fortification

In 1998 the FDA began requiring manufacturers to add folic acid to enriched breads, cereals, pasta, rice and other grain products.

Projected to increase folic acid intake by 100 mcg/day, but actually increased it by about 190 mcg/day.

Other Countries also have established folic acid fortification programs Canada, Costa Rica, Chile,

South Africa

Folic Acid Fortification

Cereals with Folic Acid

The Following cereals contain 100% of the Daily Value of folic acid per serving.

Is your cereal on the list?

Upper Limits

No UL for dietary folate because absorption is limited

UL for synthetic folic acid is 1000 mcg for adults

FDA limits amount of folic acid in non-prescription supplements to 400 mcg Over-the-counter, prenatal

supplements can contain 800 mcg

Health Risks Masks B-12 deficiency,

which leads to neurological damage

New studies show it may accelerate development of preneoplastic lesions areas that proceed

development of tumors

Chemical Structure

Consists of 3 parts: Pteridine Para-aminobenzoic acid

(PABA) Glutamate

Monoglutamate Only one glutamate

molecule attached Folic acid

Polyglutamate Multiple glutamate

molecules attached Dietary folate

Folate in the Body

Absorption Folate polyglutamates

must be broken down to monoglutamate form By enzymes called

“folate conjugases” Mono form is actively

transported across intestinal wall Large doses of

supplemental folic acid can be absorbed here by passive diffusion

Mono travels from intestine to portal vein to liver

Storage and Transportation It is either stored in the

liver Or released into blood for

delivery to cells Once in cell it is

converted back to polyglutamate form, which traps it there

Functions

Folate & B12The Folate “Trap”

B12

Deficiency:How is it measured?

Serum Folate Indicator

>3 ng/mL adequate folate status

Sensitive to dietary folate intake

Might not reflect long term status

Erythrocyte Folate Concentration

>140 ng/mL adequate folate status

Research shows higher values better for preventing neural tube defects

Reflects long term status

Deficiency:At Risk Groups

People with alcohol dependence

Women of childbearing age

Pregnant women

People with malabsorptive disorders

Deficiency

Results from: Low intake Malabsorption Increased requirement Compromised utilization Certain medication use Excessive exertion

Steps in Folate Deficiency

Deficiency

Symptoms Open sores on tongue and

mouth Change of color in skin,

hair and fingernails

Effects of Deficiency Megaloblastic anemia

Weakness & fatigue Trouble concentrating Irratibility Headache Heart palpitations Shortness of breath

Neural tube defects in pregnancy Spina bifida

Research:Current Application

Currently research shows that folate status in women who are pregnant or capable of becoming pregnant significantly effects outcome of NTD in pregnancy.

Science suggests folic acid use could reduce NTD by 50-90%

Applied through the folate fortification program and well as the increased RDA for pregnant women

Research:Evidence Analysis Library

Before & after study of patients with heart failure

Sample size=14, 12 males, 2 females

Given 0.8 mcg folate, 3 mcg pyridoxine, 0.5 mcg B12

Period of 6 weeks

Results May result in beneficial outcomes for

patients Possible benefits: decreased

homocysteine levels,arterial blood pressure and improvements in left ventricular volume and life scores

For the patient with heart failure, is there evidence to suggest that supplementing with folate and or B12 provides beneficial outcomes?

Research:Future Application

Cancer Studies suggest inverse

relationship b/w folate status and risk of various cancers

Research is mixed and depends on how much is taken and when

Modest amount, before cancer development, decrease risk; high doses, after development, speed progression

Cognitive Function Correlations between low

serum folate concentrations and poor cognitive function and higher risk of dementia and Alzheimer's disease

BUT when used folic acid supplementation as treatment for these conditions was shown to have no effect

Research:Future Application

Depression Research shows that folate

does play a role in depression

Those with Low folate levels are more likely to suffer from depression and may not respond to treatment with antidepressants as well

Folic acid supplements might make antidepressant med. More effective

Pre-term birth and congenital heart defects Folic acid supplementation

shown to lengthen mean gestational age, lowering risk of pre term birth

Also, suggests a link between folic acid and multivitamin use and a lower risk of heart defect in newborns

Case Study

Sarah 27 year old. Female Pregnant with her first

child Has read a lot of

information talking about folate in relation to pregnancy

She is extremely worried that she is not getting enough folate in her diet and she is looking for help.

What is the RDA of folate for sarah? General and Specific.

If Sarah came to you looking for ways to increase her intake, what would you suggest?

Sarah wants to know why folate is so important during pregnancy, what would you tell her?

Should she have been monitoring her folate intake before becoming pregnant?

Review

http://www.youtube.com/watch?v=AZLudkA0qz4

Sources