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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Research » Publications at this Location » Publication #93602
Title: FOLATE NUTRITURE ALTERS CHOLINE STATUS OF WOMEN AND MEN FED LOW CHOLINE DIETS

Author
item Jacob, Robert
item JENDEN, DONALD - UCLA SCHOOL OF MEDICINE
item ALLMAN-FARINELLI, MARGARET - UNIVERSITY OF SYDNEY
item SWENDSEID, MARIAN - UCLA SCHOOL PUBLIC HEALTH

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Choline and folate are B vitamins that are both needed for growth of healthy cells and can substitute for each other in some biochemical reactions. In studies with rats, low intake of one of the nutrients increases the dietary requirement for the other. To determine whether the requirement for choline is dependent on folate intake in humans, we measured the effect of various folate intakes on body choline status of healthy adult women and men. In two separate studies, 10 women (49-63 yr) and 11 men (33-46 yr) were housed in the Center's metabolic unit and fed a low choline diet with folate intakes varying from 13 to 280% of the 1989 Recommended Dietary Allowances for folate (180 and 200 microgram for women and men, respectively). The low folate and low choline intakes resulted in mild folate deficiencies, and average blood choline decreases of 25% and 28% in the women and men, respectively. No severe folate or choline deficiencies occurred, as measured by blood and liver function tests. The decreases in blood choline returned to normal when extra folate was added back to the diet. The results show that the dietary requirement for choline is greater when folate intake is low because choline is used more to compensate for lack of folate. To maintain normal levels of blood choline and phosphatidylcholine, important components of cell membranes and a neurotransmitter, at least 250 milligrams per day of dietary choline is needed when folate intake is low. Choline is found in high protein foods such as meats, diary, and soy products, while folate is found in plant foods, especially legumes, green vegetables, and citrus. Eggs, nuts, and liver contain ample amounts of both nutrients.

Technical Abstract: Choline and folate share common methylation pathways and have been shown to be metabolically inter-related in rat studies. To determine whether choline status is related to folate intake in humans, we measured the effect of controlled folate depletion and repletion on plasma choline and phosphatidylcholine concentrations of 11 healthy men (33-46 y) and 10 healthy women (49-63 y) in two separate metabolic unit studies. Total folate intake was varied by supplementing low folate (25 and 56 ug/d for men and women, resp.) and low choline (238 and 147 mg/d) diets with pteroylglutamic acid for 2-6 wk following folate depletion periods of 4-5 wk. The low folate/choline intakes resulted in subclinical folate deficiencies, mean plasma choline decreases of 28% and 25% in the men and women, respectively, and a plasma phosphatidylcholine decrease of 26% in the men (P < 0.05). No functional choline deficiency occurred, as measured by serum transaminase and lipid concentrations. The decreases in choline status measures returned to baseline or higher upon folate repletion, and were more responsive to folate repletion than plasma folate and homocysteine. Feeding methionine supplements to the men did not prevent the choline depletion, indicating that folate is a critical limiting nutrient for these methylation pathways. The results indicate that: 1) choline is utilized as a methyl donor when folate intake is low; 2) the de novo synthesis of phosphatidylcholine is inadequate to maintain choline status when intake of folate and choline is low; and 3) dietary choline is required by adults in an amount greater than 250 mg/d to maintain plasma choline and phosphatidylcholine when folate intake is low.