The Choline Chronicles: Sorting Facts from Fiction


Adequate choline intake is a must during this critical stage of life.
There are several forms of supplemental choline available for use in dietary supplements.
The Choline Chronicles II: Sorting Facts from Fiction

This powerhouse nutrient is a key player in the world of reproductive health for both men and women. For women, it supports rapid cell division and growth (1), and in men, it regulates sperm membrane structure and fluidity and plays a vital role in sperm growth and fertilizing capacity (2). Choline is essential for creating cell membranes, neurotransmission (the transfer of information between neurons), methyl metabolism, and brain development and tissue expansion for baby* (3, 4). Throw in the potential benefits of supporting neural tube development (aka baby's brain and spinal cord), and we can start to understand why finding a prenatal with adequate choline is a fertility must-have.*

Join us as we dive into commonly asked questions about choline bitartrate (if you missed the first installation of The Choline Chronicles installation about the benefits of choline, you can check it out here!). While there are several forms of supplemental choline available for use, we’ll help break down why we chose choline bitartrate for our Women’s Prenatal Multivitamin and Men’s Multivitamin, taking a look at the combined evidence as a whole when it comes to choline form, quality, and safety.

Why choline bitartrate?

The forms of choline commonly used in dietary supplements include choline bitartrate, phosphatidylcholine, and lecithin (which is a source of phosphatidylcholine) (5). When selecting the most appropriate form of choline, it's essential to consider how each form will impact the final product. For example, some forms of choline, like sunflower lecithin, may not be suitable for a powdered formula due to potential texture alterations and the risk of clumping issues. Similarly, phosphatidylcholine has only 13-15% choline by weight. You'd need to take more capsules to get the same amount of choline. Choline is a very bulky nutrient that is notably large in size, making it difficult to "fit" into a supplement. You’ll often see prenatal supplements put tiny amounts in their products or skip it altogether. Ultimately, choline bitartrate stands out as the optimal and extensively researched choice among the available options, particularly when considering the needs of pregnant women.

Does choline bitartrate increase TMAO?

TMAO is formed in the body through a complex process involving our gut microbiota (all microorganisms living inside our gut). And it’s not just choline bitartrate that can create TMAO. Compounds like betaine (found in seafood, beets, spinach, and whole grains), l-carnitine (found in chicken, fish, red meat, and dairy), and phosphatidylcholine (found in eggs, seeds, and some legumes) ALL produce trimethylamine (TMA), which enters our bloodstream and is later turned into TMAO by our liver (6). But is TMAO a bad thing?

Understanding the research and study populations

Studies examining the associations between TMAO and cardiovascular disease (CVD) aren’t perfect. The link between TMAO and heart health has been the focus of research that concluded that elevated levels of TMAO may be associated with an increased risk of heart disease. However, it’s important to note that this is an ever-changing area of research, and it requires additional work to understand these links and their associated health implications fully. Bottom line: there has been no conclusive research on this link, and a lot of study design issues that should make one question their validity.  

Studies examining associations between choline and TMAO are often conducted in populations that do not necessarily reflect optimal health. For example, these studies may be performed on people with pre-existing health conditions, less-than-ideal dietary habits, or other factors influencing the results (7). This makes their findings challenging to apply to the population as a whole, and as a result, the impact of choline on TMAO levels should be interpreted with caution. After all, confounding variables in research are the biggest red flags for whether or not we can use the study results. 

The adequate intake level for choline among pregnant and breastfeeding women is 450 mg and 550 mg per day, respectively (5). The tolerable upper limit for choline intake (set for safety) is 3500 mg daily (5). Many studies on choline bitartrate look at exceptionally high doses of supplemental choline (≥ 1000 mg per day) or include study populations unrelated to pregnancy (e.g., animal studies, male populations only, tiny study sample sizes). Furthermore, these studies often overlook related and vital factors like individual genetic variations and differences in gut microbiomes, making it challenging to automatically extrapolate their findings to the broader population, particularly in assessing risks. There is a need for additional research to provide a more comprehensive understanding of choline's impact here, especially in the context of pregnancy.

Having considered the typical dietary needs from population research and of clients over the past two decades in practice, Ayla determined that the most commonly required quantity of choline aligns with an average intake of approximately 200 - 300 mg per day, which is why you’ll find 300 mg of choline per serving in our Women’s Prenatal Multivitamin. This assessment is supported by data analysis from the 2013 - 2014 National Health and Nutrition Examination Survey (NHANES), revealing an average daily intake of 278 mg among women (5). Incorporating a supplement that contains adequate amounts of choline into a focused diet can help ensure you are getting everything you need to keep yourself healthy and provide the proper nutritional support for your baby, no matter where you are in the conception process.

Can certain microbes in our gut contribute to TMA (and therefore TMAO) creation?

The composition of each person's microbiome can vary, and research suggests that different bacterial species may have differing abilities to break down choline. The scale of TMA production is influenced by the composition of an individual's microbiota (7). Increased TMA and TMAO levels have been associated with higher levels of certain bacteria (7), suggesting that with further research, probiotics may reduce circulating levels of TMAO (7). This research also points to the importance of maintaining a healthy gut and diverse gut microbiota, given that individual dietary habits may play a crucial role, with emerging research suggesting that adopting positive nutritional habits may help reduce TMAO levels (7). Research indicates that our genetics and co-metabolism (where two or more components break something down) also play a role in TMAO creation (7), highlighting this research area's complexity. Understanding the complex relationship between choline, the gut microbiome, and the creation of TMAO is crucial in understanding their ability to impact our health. Research in this area is evolving, and further work is needed to deepen our understanding of this area of study. One thing we can say for certain? Supporting your gut health is foundational for health and always important.

The importance of choline quality

Determining the quality of choline supplements involves assessing various factors. At FullWell, we're committed to delivering scientifically supported formulas with bioavailable forms. Our evidence-based approach ensures that each supplement is carefully formulated to provide maximum efficacy and support for fertility and well-being, backed by the latest science. We care deeply about where our ingredients come from and only partner with suppliers whose practices emphasize quality, science, and responsibility. Better ingredients mean better potency, absorption, and digestibility — and ultimately, better fertility health. 

Our manufacturing process is transparent and overseen by our senior head of quality in collaboration with scientists and health practitioners at every stage. Each formula is verified to ensure the right amount of active ingredients for the best results possible. Each batch is tested in-house for contaminants, allergens, and heavy metals, and we always have an independent, certified lab confirm our results for every batch. 

Risk versus benefit

In summary, we must weigh the potential risks and benefits of choline supplementation in pregnancy. There is a substantial body of evidence supporting the many positive impacts of choline for general health and that of mom and baby, which currently outweigh the several studies on TMAO that have such significant limitations that conclusions cannot be made from them. While it is essential to acknowledge that further research is necessary to establish a link between choline bitartrate and TMAO and whether elevated TMAO is even problematic, we recommend weighing the many benefits of choline when discussing your individual needs with your healthcare professional. This isn’t a nutrient to skip during this critical stage of life. 

Women's Prenatal Multivitamin
300 mg Choline
FullWell Women's Fish Oil
Fertility Trio for Two
Choline (and more) for both eggs and sperm
* The information on this website is provided for educational purposes only and should not be treated as medical advice. FullWell makes no guarantees regarding the information provided or how products may work for any individual. If you suffer from a health condition, you should consult your health care practitioner for medical advice before introducing any new products into your health care regimen. For more information, please read our terms and conditions.