Betaine and Choline may be considered as methyl donors
Diet Betaine
Homocysteine Betaine
Although choline is not by strict definition a vitamin, it is an essential nutrient. Despite the fact that humans can synthesize it in small amounts, choline must be consumed in the diet to maintain health
The Adequate Intake (AI) ranges from 400 to 600 mg/ for adults (more details).
J Nutr. 2010 May;140(5):975-80. Epub 2010 Mar 10.
Choline intake exceeding current dietary recommendations preserves markers of cellular methylation in a genetic subgroup of folate-compromised men. 2010
Shin W, Yan J, Abratte CM, Vermeylen F, Caudill MA.
Human Nutrition and Food Science Department, Cal Poly Pomona University, Pomona, CA 91768, USA.
Abstract
Severe choline deficiency adversely affects cellular methylation and DNA integrity, with potentially serious implications for disease risk. As part of a 12-wk controlled choline intervention study conducted in folate-compromised Mexican-American men (n = 60; 18-55 y) differing in the methylenetetrahydrofolate reductase (MTHFR) C677T genotype (21 677CC, 29 677TT), this study evaluated the effects of varied choline intakes (300, 550, 1100, and 2200 mg/d) on the change (i.e. wk 12-0) in markers of cellular methylation and DNA integrity. Choline intake affected the change in plasma S-adenosylmethionine (P = 0.044), with decreases tending to be greater (P < or = 0.08) in the 300 and 550 mg/d groups than in the 2200 mg/d group. Choline intake also interacted with the MTHFR C677T genotype to affect the change in genomic DNA methylation and DNA damage. In men with the MTHFR 677CC genotype, choline intake affected (P = 0.007) the change in DNA methylation, with a greater decrease (P < 0.02) in the 300 mg/d group than in the 1100 and 2200 mg/d groups. In men with the MTHFR 677CC genotype, choline intake also affected (P = 0.047) the change in DNA damage, with the increase tending to be greater (P = 0.07) in the 550 mg/d group than in the 2200 mg/d group. Choline intake did not affect these variables in men with the MTHFR 677TT genotype. Overall, these data suggest that choline intake exceeding current dietary recommendations preserves markers of cellular methylation and attenuates DNA damage in a genetic subgroup of folate-compromised men.
la colina della
Solgar è dosata piuttosto bassa.
La formulazione prevede
colina bitartrato 350 mg
considera che x questo sale il titolo in colina (quello che ci serve) è il
41%, quindi da una capsula si ricavano solo 350×41/100 = 143,5 mg di
colina. Mi pare poco, io tornerò a chiedere un galenico dosato più alto
(il fabbisogno RDA è 550 mg di colina).
Nature's Plus
Carnitine and choline supplementation with exercise alter carnitine profiles, biochemical markers of fat metabolism and serum leptin concentration in healthy women. 2003
- We sought to determine the effects of supplementary choline, carnitine and a combination of the two with or without exercise on serum and urinary carnitine and biochemical markers of fatty acid oxidation in healthy humans. Nineteen women were placed in three groups: 1) placebo, choline or carnitine preloading period of 1 wk followed by 2) supplementation with choline plus carnitine during wk 2-wk 3 and 3) all groups exercised in wk 3. Although there were no changes in the placebo group, serum and urinary carnitine decreased in the choline-supplemented group during wk 1. Introduction of carnitine to the choline group restored serum and urinary carnitine. Serum and urinary carnitine increased during wk 1 in the carnitine-supplemented group and, although the introduction of choline to this group depressed serum and urinary carnitine, they remained significantly greater than control. Serum beta-hydroxybutyrate and serum as well as urinary acetylcarnitine were elevated by the supplements. A mild exercise regimen increased the concentration of serum beta-hydroxybutyrate, and serum and urinary acylcarnitines; it also decreased serum leptin concentrations in all groups. The effects of supplements were sustained until wk 2 after cessation of choline plus carnitine supplementation and exercise. We conclude that the choline-induced decrease in serum and urinary carnitine is buffered by carnitine preloading, and these supplements shift tissue partitioning of carnitine that favors fat mobilization, incomplete oxidation of fatty acids and disposal of their carbons in urine as acylcarnitines in humans.
