It is said to be a nutrient vital for helping make healthy babies - and for our memory - but chances are you've never heard of it and don't know you're missing it.
International research shows most people are likely deficient in the nutrient - known as choline - while a leading New Zealand nutritionist says it is understandable many of us are unaware of it.
Professor Elaine Rush, scientific director of the New Zealand Nutrition Foundation, agrees even many health professionals are not all that familiar with choline so "how can the general public be expected to know about it."
Although 90 per cent of Americans are not getting enough choline (according to a 2016 study published in the Journal of the American College of Nutrition) - a percentage experts believe is likely to be similar in New Zealand and Australia - the good news is many of our most common foods are rich in choline, none more so than eggs.
Rush, who refers to eggs as "little power packs of nutrients", says they are, along with liver and peanuts, three of the best sources of choline and eating two eggs a day will provide well over half the recommended daily choline intake (550mg for men and 425mg for women).
A relative newcomer to the ranks of required nutrients - it was only acknowledged as such by the US Institute of Medicine in 1998 - research shows it (choline) is important for various functions in the body including the liver and muscles, for brain health and for helping store and process memories.
It is also crucial for pregnant women and the health of their babies. Professor Marie Caudill, an expert on the impact of choline on maternal and infant health at Columbia University in the US, says women who supplement with choline give birth to babies with lower levels of stress hormones, a factor likely to have lifelong benefits for the newborn's future brain health and a reduced risk of developing chronic diseases later in life.
Yet despite its health benefits choline is under-consumed and under-appreciated. Taylor Wallace, an affiliate professor in the Department of Nutrition and Food Studies at George Mason University in Virginia says there "isn't enough awareness about choline even among health-care professionals" and that therefore "it is not surprising 90 per cent of Americans and 92 per cent of pregnant women do not achieve the recommended intakes."
Jen Houchins, the director of nutrition research at the Egg Nutrition Centre (ENC) in the United States, said in a 2018 report choline was ranked last among common nutrients recommended for a healthy diet.
Meanwhile Rush, an internationally recognised research leader with expertise in nutrition among other health areas, says eating two boiled eggs a day will produce about 400mg of choline (the nutrient is contained in the yolk, the white being a good source of protein).
This is an amount well on the way to meeting the daily intake recommendations jointly set in New Zealand by the Ministry of Health and the Australian National Health and Medical Research Council.
Choline is an essential nutrient (meaning most of it must come from food because the body produces only small amounts), and Rush says the best way to obtain the required amounts - and to maintain an overall healthy diet - is to eat wholefoods together with sensible amounts of fruit and vegetables.
Eggs, she says, are one of the best wholefoods available. "Eggs are such a brilliant solution and not just for choline. They are affordable, don't need to be refrigerated and are great to add to a child's lunchbox; they are a good investment and I highly recommend them.
Rush says recent research has debunked the myth that eggs are bad for you. The Heart Foundation, Ministry of Health and the Nutrition Foundation have all given eggs a big tick for nutrition, protein and vitamins while the Heart Foundation says even those at risk of heart disease can eat 6-7 eggs a week.
Despite its importance, Rush says choline is not a one nutrition fix: "It is one of thousands of nutrients, it is a team player."
As well as eggs, Rush says about half a cup of cooked liver (from beef, lamb or chicken) contains 360mg of choline, one cup of kidney beans and one cup of peanuts each contain 90mg while one tablespoon of peanut butter gives around 10mg. Meats such as beef (an 85g piece has 430mg of choline), organ meats like brain, kidney and giblets, soy products and legumes (peanuts, beans and peas) are other good sources.
In the US Wallace, who as well as his role at George Mason University is recognised as a leading food science and nutrition expert, says the bottom line is health professionals need to be aware of food sources of choline.
In an article published earlier this year in Nutrition Closeup, an ENC publication he said: "While data indicates a need……to increase plant foods in the diet this should not mean eliminating nutrient-dense animal-derived foods such as eggs that contain higher levels of choline."