Choline has only recently been discovered and acknowledged as a required nutrient in 1998. Although, your body makes choline, the major of your choline requirement comes from your diet – however many people do not meet the recommended intake of this nutrient.
What is choline?
Choline is an organic, water-soluble compound – it is neither a vitamin nor a mineral. It is often grouped with the vitamin B complex, due to its similarity and the role it plays in similar vital bodily functions. It has an impact in liver function, healthy brain development, muscle movement, nervous system and metabolism.
What role does choline play in the body?
Choline plays an important role in the following body processes:
- Cell structure: It is needed to make fats that support the structural integrity of cell membranes.
- Cell messaging: It is involved in the production of compounds that act as cell messengers.
- Fat transport and metabolism: It is essential for making a substance required for removing cholesterol from your liver.
- DNA synthesis: Helps in the process of DNA synthesis
- Healthy nervous system: This nutrient is required to make acetylcholine, an important neurotransmitter.
How much Choline do you need?
The reference daily intake (RDI) for choline has not yet been determine, however the adequate intake (AI) values have been set (425-550mg/day). Requirements differ according to one’s genetic makeup and gender.
The recommended AI values for choline are as follows, and differ per age group:
- 0–6 months:125 mg per day
- 7–12 months:150 mg per day
- 1–3 years:200 mg per day
- 4–8 years:250 mg per day
- 9–13 years: 375 mg per day
- 14–19 years: 400 mg per day for women and 550 mg per day for men
- Adult women: 425 mg per day
- Adult men: 550 mg per day
- Breastfeeding women: 550 mg per day
- Pregnant women: 450 mg per day
What are the risks of Choline deficiency?
Choline deficiency is associated with liver and/or muscle damage. Individuals at an increased risk of choline deficiency; Endurance athletes, high alcohol intake, postmenopausal women and pregnant women (unborn babies require choline for development).
Food sources of Choline
Dietary sources are generally in the form of phosphatidylcholine from lecithin, a type of fat. The richest dietary sources of choline include:
Beef liver:1 slice (68 grams) contains 290 mg.
Chicken liver:1 slice (2 68 grams) contains 222 mg.
Eggs:1 large hard-boiled egg contains 113 mg.
Fresh cod:3 ounces (85 grams) contain 248 mg.
Salmon:A 3.9-ounce (110-gram) fillet contains 62.7 mg.
Cauliflower:A 1/2 cup (118 ml) contains 24.2 mg.
Broccoli:A 1/2 cup (118 ml) contains 31.3 mg.
Soybean oil:1 tablespoon (15 ml) contains 47.3 mg.
PEMT (rs7946) - Phosphatidylethanolamine N-methyltransferase
The PEMT gene is involved in maintaining cell membrane structure. Without proper membrane function, cells die. Phosphatidylcholine provides the main structural component of the cell membrane. PEMT is the only enzyme that can produce choline in the human body. PEMT activity is stimulate by oestrogen, thus certain gene variants have more of an impact on males and post-menopausal females. Choline plays an important role in the methylation cycle. Your body’s need for choline from the diet depends in part on your folate intake, and your body’s methylation capability. Choline, acts as a methyl donor in the methylation cycle and with low folate or decreased enzyme efficiency in the folate pathways, your choline requirement may increase. Choline is a major source of methyl groups via its metabolite betaine, which catalyzes the methylation of homocysteine to form methionine. The PEMT pathway is estimated to contribute about 30% of the choline synthesised in the liver and 70% comes from dietary sources. Choline is involved in several critical roles in multiple organs including the lungs, heart, liver, stomach and brain.
Role of choline in methylation cycle. Wikimedia Commons, Public Domain
C/C – normal PEMT enzyme function
C/T – somewhat decreased PEMT enzyme function
T/T – decreased PEMT enzyme function, leading to impaired cell membrane integrity and may cause choline deficiency.
Associations with PEMT dysfunction and choline deficiency:
- Fatty liver disease in the presence of overeating (Non-Alcoholic Fatty Liver Disease) PMID 16051693.
- Breast cancer in the presence of low betaine intake.
- Memory decline (Lower phosphatidylcholine production).
- A tendency for anxiety.
- Slower conversion into homocysteine into methionine.
- Increased glutamate sensitivity, a neurotransmitter involved in memory and learning.
- Risk of sleeping disorders, not achieving deep sleep (REM).
- Increased risk for ‘leaky cells’.
- Impaired regulation of nutrients to get into cells and waste products to be removed from cells.
- Increased risk for DNA damage.
Choline is an essential nutrient that PEMT requires to synthesise phosphatidylcholine. With lower PEMT function, the needs for choline increased
(See above section for Choline dietary sources)
Supplementation and recommended intake of choline with one or two mutated allele (T):
• 550mg for men
• 425mg for women
• 450mg for pregnant women
• 550mg for breastfeeding and menopausal women
• PEMT makes the choline needed to be used by the BHMT enzyme to turn homocysteine into methionine.
• Increase susceptibility to high homocysteine levels particularly in combination with variants on MTHFR, MTR or MTRR genes.
This result may associate with increased sensitivity to anticholinergic drugs e.g.
• anti-parkinson's medications
• benztropine mesylate
• quetiapine (Seroquel)