Betaine Supplementation and Cardiovascular Health

Potential Risks and Monitoring

Enteral administration of betaine may be converted into methylamine-N-oxide (MAO) by gut microflora and subsequently metabolized by the liver into trimethylamine-N-oxide (TMAO), potentially having a negative long-term impact on cardiovascular health 1, 2
Acute ingestion of high doses of betaine may cause a fishy body odor 2
The upper limit (UL) for adults has been defined at 3.5 g/day, as recommended by Clinical Nutrition 2
For patients with renal dysfunction, monitoring TMAO levels is recommended, as betaine metabolism may contribute to this uremic toxin 1, 2
Choline and betaine status might be quantified indirectly through their role in one-carbon metabolism, according to Clinical Nutrition 1

Betaine is used as an adjunct to treatment for patients with homocystinuria (CBS deficiency), remethylating homocysteine to methionine, as recommended by the European Heart Journal 3
For individuals with homocystinuria due to CBS deficiency who are non-responsive to vitamin treatment, betaine may be used as an adjunct to treatment along with a methionine-restricted, cystine-supplemented diet, as suggested by the European Heart Journal 3
Betaine may be particularly beneficial in conditions where methylation processes are impaired, such as in cases with MTHFR 677TT genotype, according to the European Heart Journal 3

In patients with cystic fibrosis, choline depletion (which is metabolically related to betaine) is common despite enzyme treatment and may result in liver, fatty acid, and muscle abnormalities, as reported by Clinical Nutrition 2