Which nutrients matter? Where do we find them? What do they do? Some people may feel overwhelmed by the technical details: what each nutrient is called, what each one does, and which foods contain each one. Sometimes it might seem easier to turn our heads away from all this complexity and go back to eating the way we always have.

Yet there are many books and podcasts telling us that we should change the way we eat in order to improve our health. What should we do? Change, but how? It can all be so confusing. The two of us have published many studies showing that better mental health results from improving nutrient intake. So it is important to us to help solve the confusion in order to encourage people to improve and protect their brains.

We think we have a simple solution. Understanding just one bit of terminology used in describing nutrients can help you transform your diet and improve your health. That ‘bit’ is the difference between a macronutrient and a micronutrient. Macro means ‘big’ and micro means ‘little.’

  • Macronutrients are categories that include fats, carbohydrates (carbs) and proteins. Every package of food that you buy lists at least those three macronutrient categories and sometimes more. We need these to grow, build and repair tissues, help with cell membrane integrity, store and provide energy. But Americans are generally not lacking in macronutrients, and we think the almost exclusive focus on them tends to overshadow the importance of micronutrients.  
  • Micronutrient is the term usually used for one of the roughly 30 vitamins and minerals that we need to consume. You likely know about some (calcium, vitamin C, magnesium) though others may be less familiar (especially trace minerals like molybdenum, selenium). You will never find a package of food that lists all 30 micronutrients. Government requirements change every few years, but right now Americans can expect to see at least four: vitamin A, calcium, iron, and potassium. And each one states % DV (Daily Value), which refers to the amount your government says you should consume every day to protect your health.

Now let’s do an experiment. Every time you open a package of something to eat or to cook with, look at those four micronutrients. Also notice whether any other micronutrients are listed. Better yet, grab a piece of paper and make a chart like this one, which we made from common, popular products:

Product% DV vit A% DV calcium% DV iron% DV potassium

What this example tells you is that after eating these three packaged products you have not come close to reaching 100% of your DV for any of those four micronutrients. And as we explained, there are more than 26 other micronutrients for which information is not even provided. If the food is highly processed, chances are those other micronutrients aren’t even contained within that food product. But the consumer will never know, because food manufacturers are not required to list them!

Is this a problem? Probably. Americans are generally consuming suboptimal levels of virtually all of the micronutrients. Dietary surveys show that nutritional deficiencies, based on eating a typical western diet, are simply far too common. To name a few survey results, 94% of the US population do not even meet the daily requirement for Vitamin D, 89% for Vitamin E, 52% for magnesium, 44% for calcium, 43% for Vitamin A and 39% for Vitamin C. The message: some Americans are severely lacking in daily intake of minerals and vitamins.

And what concerns the two of us is that it is our brains that require the most and are likely suffering the most from our poor micronutrient intake. It is time to ask this question: how are we getting an adequate intake of our micronutrients when much of what our society consumes is in packages?


  • Bonnie J. Kaplan

    PhD, Professor

    coauthor of THE BETTER BRAIN

    Currently Professor Emerita in the Cumming School of Medicine at the University of Calgary, in Alberta, Canada. Originally from Ohio, she did all her training in the U.S. She has published widely on the biological basis of developmental disorders and mental health – particularly, the contribution of nutrition to brain development and brain function. Her efforts to include nutrition knowledge in the care of people with mental health challenges has earned her a variety of awards, including the Dr. Rogers Prize (https://www.drrogersprize.org) in September 2019; and in 2017 she was selected as one of 150 Canadian Difference Makers in Mental Health, in honour of Canada’s 150th birthday. Her book The Better Brain, written with her former student Prof Julia Rucklidge (University of Canterbury, Christchurch, New Zealand) has just been published by Houghton Mifflin Harcourt.
  • Julia Rucklidge

    Prof of Clinical Psychology

    University of Canterbury

    Julia is a Professor of Clinical Psychology in the School of Psychology, Speech and Hearing at the University of Canterbury, the Director of Te Puna Toiora, the Mental Health and Nutrition Research Lab and co-author of The Better Brain published by Penguin Random House and Harper Collins in 2021. Originally from Toronto, Canada, she completed her PhD at the University of Calgary in clinical psychology. In 2000, she immigrated to New Zealand. For over a decade, she and her lab have been running clinical trials investigating the role of broad-spectrum micronutrients in the treatment of mental illness, specifically ADHD, mood disorders, anxiety and stress. Julia has over 140 peer reviewed publications, given invited talks all over the world, and is frequently featured in the media. Her 2014 TEDx talk has been viewed over 1.9 million times. She recently created a free EdX online course for the public on mental health and nutrition. Having witnessed current conventional treatments failing so many people, Julia is passionate about helping people find alternative treatments and being a voice for those who have been let down by the current public healthcare system.