Five nutrients most moms are quietly low on

This is not a supplement pitch. Most of what follows is food, and the one rule worth keeping is at the bottom: ask before you start, especially if you are pregnant, feeding a baby, or taking anything prescribed.

Iron

The one that comes up most. Iron-deficiency anaemia affects roughly 9% of American women aged 20 to 49, and rates in pregnancy are higher still. Heavy periods raise the risk considerably, and so does having had babies close together.

It is worth naming the symptoms because they get attributed to motherhood instead: exhaustion that sleep doesn't fix, breathlessness on the stairs, cold hands, a racing heart, hair falling out, and sometimes a strange urge to chew ice.

• Red meat, liver, and dark poultry meat are the most readily absorbed forms
• Lentils, beans, tofu, pumpkin seeds and dark leafy greens are the plant forms — pair them with something high in vitamin C to absorb more
• Tea and coffee with a meal reduce absorption; move them to between meals

Iron is the one to test rather than guess at. Too much is genuinely harmful, so a blood test before supplementing is worth the appointment.

Vitamin D

Made in skin from sunlight, which makes it a predictable shortfall for anyone through a northern winter, anyone mostly indoors, and anyone with darker skin, who needs considerably more sun exposure to make the same amount.

Food sources are limited — oily fish, egg yolks, and fortified foods — which is why this is one of the few where a supplement is commonly recommended rather than a fallback. Your provider can test and tell you a dose rather than you guessing at one.

B12

Only found in animal foods, so anyone eating little or no meat, dairy or eggs is at real risk, and so is anyone on long-term acid-reducing medication, which affects absorption.

Deficiency looks like fatigue and brain fog, which is to say it looks like every mother of a small child, which is exactly why it gets missed. It is easy to test.

Iodine

Needed for thyroid hormone, and requirements rise in pregnancy and while breastfeeding. Intake has drifted down as people moved from iodised table salt to sea salt and kosher salt, which mostly are not iodised.

Dairy, eggs, fish and iodised salt are the usual sources. Seaweed is a source too, but a wildly variable one — some contains far more than a daily requirement in a single portion, so it is not a reliable way to aim.

Choline

The least talked about of the five, and one most people have never heard of. It matters for the baby's brain development in pregnancy and while feeding, and surveys suggest most women fall short of the recommended intake.

Egg yolks are the standout source — two eggs gets you a meaningful way there. Liver is higher still, then meat, fish, beans and cruciferous vegetables. Notably, many prenatal vitamins contain little or none, so it is worth checking the label of the one you're taking.

The rule underneath all of it

Food first, because food brings everything else along with it and is very hard to overdo.

And then: ask before you start. Not because supplements are sinister, but because iron can be harmful in excess, some things interact with prescriptions, and a blood test costs less than a year of guessing. Take the bottle to the appointment if it's easier than explaining.