Have you heard of this vitamin-like nutrient that is essential for human health?  I admit, I must have glossed over this nutrient in my medical education, because it didn’t register on my radar other than as a supplement until a few years ago.  In this week’s article, we will explore this nutrient and some of the structures and processes it is important for.  We will then look at food sources and discuss supplementation.  

For the remainder of the year, we will follow this format when discussing specific nutrients.  In the end, we will have spent five months discussing the basics of nutrition and healthy eating and seven months taking a deep dive on each individual nutrient.  My hope is that in the end you will feel much more confident and capable in using food to support your health, and will be better able to spot and avoid costly health fads and scams.

What is Choline?

Choline is a nutrient that is produced by the body -- mostly in the liver -- in the form of phosphatidylcholine. (3)  It is sometimes called vitamin B18, but it is not technically classified as a vitamin and this naming is actually used to convince people to purchase supplements.  

The chemical structure is C5H14NO+ for all you chemistry lovers out there. (1)  From this basic structure, multiple chemicals with different purposes are created: acetylcholine, betaine, phosphatidylcholine, sphingomyelin, and glycerophosphorylcholine. (2)  Some of these compounds may be familiar to you if you have ever studied biochemistry or if you have taken supplements advertised to help with sleep or brain function, but don’t feel bad if they are all new to you.   

If you are interested in a great video overview of choline and controversies in the research behind supplementation claims, especially when considering a plant-based diet, this is a great video! 

What Does Choline Do?

Now that we have an idea of what choline is as a chemical, let’s look at what it does.  There are six major functions of choline and its metabolites within the human body.  When we look at these functions, we will be looking at life on the cellular level, which is where biochemistry happens.  This can get very technical very quickly, but I will do my best to make this information accessible and use plenty of metaphors and analogies.  Let’s jump in: 

Cell membranes: 

The basic unit of life is the cell.  This is where DNA is stored, where proteins and hormones are made, where energy is created, and so much more.  Outside of cells, different processes occur, and a separation of these two areas is key for life.  Our cell membranes provide this separation and control what goes in and out of the cell.  

Imagine a restaurant: the front of the house with the dining room full of tables and chairs, diners, waitstaff, menus, and delicious food.  In the back of the house, we have the kitchen with dishwashing and meal preparation, food storage, an office for all the business management tasks, equipment, etc.  Each area is vital for the running of the restaurant, but different activities occur in different areas.  

The cell membrane is like the wall separating the front and back of the house, and choline, in the form of phosphatidylcholine and sphingomyelin, form this structure. (2)

Nerve function: 

Our nervous system is one of the main control systems of our bodies.  We send and receive messages between our brain and all our different parts.  We think, feel, see, hear, digest, move, smell, and so much more through these electrical connections, and the basic unit of the nervous system is the nerve cell (neuron). 

Neurons are specialized cells with a unique structure.  On one end there are several arms full of receptors ready to receive signals from other cells called dendrites (like tree branches).  On the other is a long projection that sends signals out from the neuron to its destination called the axon.  At the end of the axon are tiny bubbles filled with neurotransmitters - the chemical messengers of the nervous system.  One of the most abundant neurotransmitters in the body is acetylcholine - one of the choline metabolites. (2)

Fat transport and metabolism: 

In the liver, choline as phosphatidylcholine serves a very important function: clearing fat out of the liver. (2)  When we digest and absorb fat from our food, it travels to the liver to be processed before being sent on its way.  Phosphatidylcholine is needed to package fat and cholesterol and send it out into the bloodstream.  Without adequate levels, fat accumulates in the liver and fatty liver disease can be the result.

For more on liver function, see my article Your Ever-Loving Liver.  To review fat digestion, take a look at this year’s fat article and my overview of digestion. 

Cell communication: 

Just as we live in communities as entire organisms, our cells live in communities too.  This means communication, and regulation of communication, is necessary.  Cells “talk” to each other by sending and receiving different chemicals.  Chemicals like hormones and other smaller molecules are created inside cells and then sent out into the body: into the spaces between cells, the blood, and the lymph.  Receptors on cell membranes then fuse to these chemical messages and respond in programmed ways.

A frequent analogy used when studying cellular communication is a lock and key.  Each chemical message is like a key and each membrane receptor is like a lock.  You need the right pair to come together for the lock to open.  What I’ve always found mind-blowing is the fact that most of these chemical messages end up influencing our DNA itself!  The DNA isn’t re-written, but which parts of the DNA are “turned on” to create proteins are. 

I think of it in terms of all our unique talents and abilities.  We always have them, but we don’t use them all the time - that would be chaos!  If I’m in the middle of a craniosacral therapy session with a patient, I’m not going to be simultaneously knitting a sock or making my favorite hummus recipe.  I have these skills and more at my disposal, but I don’t want them all active at the same time; I wouldn’t be able to function.  My situation will determine when each ability is needed.  Chemical messages are how our cells determine which genes (skills) to activate at which times.

There are many different chemicals that can be used as messages and many different kinds of receptors that trigger many different types of responses in many different types of cells.  This is how we get such beautiful complexity within our bodies.  Choline and its metabolites are used to create some of these messages.

Life is so amazingly impressive!

Methylation:

Methylation has been getting more attention over the past decade or so, and this is for good reason.  Remember how cell communication can result in areas of DNA being “turned on”? Methylation is a crucial part of this.  Methylation is necessary for many functions including: natural detoxification in the liver, our cardiovascular health, our nervous system function, and the production of glutathione -- one of our major antioxidants that prevents tissue damage.

The funny thing is, methylation simply means passing a single carbon atom with three hydrogens attached from one molecule to another.  It's a biochemical passing of the baton which creates effects through the entire body.

Choline is one of our major sources of methyl groups.  Another very important source of methyl groups is folate which we will address later this year.  When it comes to methylation, choline and folate tend to support each other: if you are low in choline, folate can supply the needed methyl groups and vice-versa. (2)  In nature, when you see these backup strategies, you know you are looking at a function essential for life itself. 

Osmoregulation: 

This is a fancy word that boils down to keeping water where it needs to be.  Water is a substance in the body that needs to be kept in balance.  Too little water in an area, and those cells cannot function properly; they shrivel up, and tissues die.  Too much water, and molecules that need to interact with each other will never meet, cells will burst through their membranes, and tissues will die.  Water must be in balance.  

Choline -- as its metabolite betaine -- functions to help keep water in check, especially in the kidneys. (2)

Now that we have a better understanding of what choline is and what it does, let’s look at how we get it into our bodies. 

Where Can I Find Choline?

First, look to your liver, as it produces choline every day.  Next, let’s look at food sources: (2)

Choline rich food sources: 

Animal Sources: 

• Beef liver (3 oz)  - 356 mg 

• Egg (1) - 147 mg

• Beef (3 oz) - 97 mg

• Scallops (3 oz) - 94 mg

• Salmon (3 oz canned) - 75 mg

• Chicken breast (3 oz) - 73 mg

• Cod (3 oz) -71 mg

Plant Sources: 

• Wheat germ (1 cup) - 202 mg

• Brussels sprouts cooked (1 cup) - 63 mg

• Broccoli cooked (1 cup) - 63 mg

• Peanut butter (2 Tbsp) - 20 mg

Choline Supplements: 

There are many different supplements that contain choline or choline metabolites.  Choline bitartrate, phosphatidylcholine, and lecithin are particularly easy to find. 

Applications:

First, when it comes to optimal health and function, no recommendation for daily intake of choline has been established.  Second, your need for choline is influenced by many different factors, including your ability to metabolize folate, so needs vary quite a bit from person to person.  That being said, an adequate intake of 425 - 550 mg of choline seems to provide protection from fatty liver disease.  (2)

On the other end, 10,000 - 16,000 mg of choline intake is associated with symptoms of toxicity.  These include a fishy body odor, vomiting, increased salivation, and increased sweating. (2)

Food or Supplements?  Both?

For those consuming animal products such as eggs, choline deficiency is highly unlikely and supplementation doesn’t seem indicated. 

However, for those who follow a strictly vegan diet and are not including choline-rich food sources like brassica vegetables, supplementation may be helpful.  This is especially true for those with genetic changes in methylation such as having a Methylenetetrahydrofolate reductase deficiency polymorphism (MTHFR).  

I personally follow a vegan diet and have a documented MTHFR variant.  To account for this, I choose to take a multivitamin that includes choline bitartrate and eat lots of brassica vegetables. 

I hope this week’s article was full of new and useful information for you both, about choline and about bodily functions.  I find it amazingly easy to geek out on anatomy and physiology and get very excited about sharing this information with others!

Next Week:

Next week we will explore flavonoids, a family of nutrients that are particularly abundant in fruits and vegetables.  Like choline, flavonoids are not considered a vitamin, but they are essential for our bodies to function.  

References

1. National Center for Biotechnology Information (2021). PubChem Compound Summary for CID 305, Choline. Retrieved June 2, 2021 from https://pubchem.ncbi.nlm.nih.gov/compound/Choline.

2. Higdon, J, “Choline”, Linus Pauling Institute Micronutrient Center, 2000, updated 2015, Accessed 06/02/2021 https://lpi.oregonstate.edu/mic/other-nutrients/choline

3. National Institutes of Health, Office of Dietary Supplements, “Choline”, March 29, 2021, Accessed 06/02/2021 https://ods.od.nih.gov/factsheets/choline-healthprofessional/