Nutrition during childhood shapes everything from brain development and immunity, to mood regulation, growth, energy, and long-term health habits. Yet even in well-fed homes, many kids fall short on key nutrients. Between picky eating, busy days, modern convenient (yet often heavily processed) food options, limited guidance around childhood nutrition, and nutrient-depleted soils, these gaps can appear far more easily than most families expect.
As a future holistic nutrition professional, understanding the most commonly missing nutrients (and how to help families fill the gaps with whole foods) will support your work with parents, caregivers, and children of all ages.
Here are the top 10 nutrients kids often lack, and where to find them through real food sources.
1. Iron
Iron deficiency is the most common nutrient deficiency in children, and it can directly affect energy, learning, and behavior.
Why kids need it:
- supports cognitive development
- carries oxygen to cells
- helps maintain energy and focus
Best food sources:
- grass-fed beef & turkey
- lentils and beans
- spinach
- eggs
- pumpkin seeds
- blackstrap molasses
Tip: Pair plant-based iron with vitamin C (like citrus or berries) to boost absorption.
2. Vitamin D
Because of indoor lifestyles, sunscreen, and northern climates, many kids aren’t getting enough.
Why kids need it:
- supports strong bones
- boosts immune function
- helps regulate mood
Best food sources:
- egg yolks
- fatty fish (salmon, sardines)
- sunlight exposure (safe, limited amounts)
Supplementing is often key, especially in colder climates. Consult a practitioner to find appropriate guidance.
3. Omega-3 Fatty Acids (DHA & EPA)
Critical for growing brains and emotional regulation, yet often too low in kids’ diets.
Why kids need it:
- supports cognitive development
- helps with attention, focus, and mood
- reduces inflammation
Best food sources:
- salmon, mackerel, sardines
- cod liver oil
- chia, flax, and hemp seeds
- algae-based DHA for plant-based families
4. Magnesium
Magnesium is an essential mineral that supports over 300 processes in the body, yet many kids consume far less than needed.
Why kids need it:
- supports sleep and nervous system regulation
- helps with muscle relaxation
- supports healthy digestion
- plays a role in energy production
Best food sources:
- nuts & seeds
- oats
- leafy greens
- bananas
- beans
- cacao (yes – dark chocolate counts!)
5. Fibre
Most kids don’t get enough fibre, especially with diets high in processed snacks and low in whole foods.
Why kids need it:
- supports healthy digestion
- stabilizes blood sugar
- feeds and nourishes beneficial gut bacteria
- reduces constipation
Best food sources:
- fruits & vegetables
- whole grains
- chia, flax, and hemp seeds
- beans and lentils
- oats
6. Calcium
Calcium intake drops sharply when kids transition away from dairy, but their bones still need plenty. Coupling food sources of calcium with sources of vitamin D, K, and magnesium can also support better absorption.
Why kids need it:
- supports strong bones and teeth
- helps nerves and muscles function properly
Best food sources:
- yogurt, kefir, cheese
- fortified plant milks
- tofu
- broccoli
- almonds
- chia seeds
7. Zinc
Zinc is important for immune strength and appetite regulation, yet it’s commonly low – especially in picky eaters.
Why kids need it:
- supports growth and development
- promotes immune health
- helps maintain appetite and taste perception
Best food sources:
- pumpkin seeds
- chickpeas
- cashews
- whole grains
- eggs
- seafood (especially oysters)
8. B Vitamins (Especially B6, B12, Folate)
These vitamins support mood, energy, and metabolism – but are often low, especially in vegetarian families or kids who avoid animal products.
Why kids need them:
- supports brain development
- boosts energy
- supports methylation & detox pathways
- helps with mood regulation
Best food sources:
- eggs
- meat and poultry
- nutritional yeast
- beans & lentils
- leafy greens
- whole grains
9. Vitamin C
Surprisingly, many kids don’t meet their daily needs – especially if they avoid fruits or rely on juice instead of whole foods.
Why kids need it:
- boosts immune strength
- supports skin healing and collagen
- improves iron absorption
Best food sources:
- oranges, strawberries, kiwi
- bell peppers
- broccoli
- tomatoes
- pineapple
10. Iodine
Iodine deficiency is on the rise due to reduced use of iodized salt and fewer seafood-rich diets.
Why kids need it:
- supports healthy thyroid function
- fuels brain development
- supports growth and metabolism
Best food sources:
- seaweed snacks
- iodized salt
- fish
- some dairy products
Why Do Deficiencies Happen?
Even in the most well-intentioned families, nutrient gaps can sneak in more easily than expected. Many kids go through picky eating phases, rely on quick, low-protein breakfasts, or snack mostly on packaged foods throughout the day. Add in food allergies or dietary restrictions, nutrient-depleted soils, and the reality of busy schedules that make balanced meals harder to plan, and it becomes clear that deficiencies aren’t usually about a lack of effort or care, but circumstance.
As holistic nutrition professionals, it becomes clear just how common these deficiencies are fairly quickly in practice – But the good news is that bridging these gaps doesn’t require a massive overhaul. With practical, whole-food education and a few easy swaps, it’s possible to support a child’s development, behavior, and overall well-being in a way that feels doable and empowering for all. This work is more important in today’s modern world than ever before!
Practical Tips for Parents, Practitioners, and Caregivers
Here are a few simple steps to move the needle forward:
1. Build a Balanced Plate: Include protein, healthy fats, fibre, and colourful fruits/veggies at every meal.
2. Add Nutrients, Don’t Restrict: Encourage nutrient boosters: hemp seeds, berries, nut butters, beans, leafy greens, and eggs. It’s less about what you have to cut out, and more about what you can add in!
3. Make Snacks Work Harder: Swap crackers/cookies for:
- smoothies
- yogurt + fruit
- hummus + veggies
- chia pudding
- trail mixes
4. Get Kids Involved: Kids who help choose and prepare meals are more likely to eat them. Encourage your children to make their own smoothies, and talk about the ingredients as they add them. Talk about the omega-3 in hemp hearts, the fiber and vitamin C in strawberries, and the zinc in their pumpkin seeds. This helps them connect different foods with how it can help them feel, often resulting in more engagement and fewer mealtime battles.
5. Consider Targeted Supplementation: Only as needed, and always with professional guidance.
Final Thoughts
Understanding nutrient gaps in childhood is essential for every holistic nutrition professional. These early years directly influence a child’s growth, cognitive development, mood, immune health, and lifelong habits. With simple, whole-food strategies and compassionate guidance, you can help families raise thriving, well-nourished kids – one nutrient-rich meal at a time.
If you’re ready to deepen your confidence and truly support families at this foundational stage, our Childhood Nutrition Specialist Course was designed to give you practical, evidence-informed tools you can use right away. From identifying common nutrient gaps to creating realistic, family-friendly solutions, this training empowers you to guide parents with clarity, compassion, and credibility.
