Discover the 5 most common vitamin deficiencies in kids, signs to watch for and how to prevent them with food and supplements.
As parents, we all want our kids to thrive. But even with the best diets, children can miss out on key vitamins and minerals—especially if they’re picky eaters or on restricted diets. Deficiencies in nutrients like vitamin D, iron, and B Vitamins can affect everything from energy and focus to immunity and bone health.
In this blog, I’ll share the top 5 vitamin deficiencies in kids, symptoms to watch for, and easy ways to prevent them.
1. Vitamin D – The Sunshine Vitamin
Why kids need it:
Vitamin D supports strong bones, teeth, and a healthy immune system.
Signs of deficiency:
- Frequent colds or infections
- Fatigue or low mood
- Bone pain or delayed growth
Why it’s common:
Most kids don’t get enough sun exposure, especially during winter months. Few foods naturally contain vitamin D.
What to do:
Include vitamin D-rich foods like fatty fish, fortified milk, or fortified plant-based alternatives. And make sure they take a Vitamin D supplement daily! (600IU for age 1+)
2. Iron – The Energy Booster
Why kids need it:
Iron helps transport oxygen through the blood, supporting energy, brain development, and focus.
Signs of deficiency:
- Pale skin
- Tiredness or irritability
- Poor concentration
- Slow weight gain
Why it’s common:
Kids who don’t eat much red meat or plant-based children are most at risk.
What to do:
Add iron-rich foods like lean meat, beans, spinach, and iron-fortified cereals. Pair plant-based iron with vitamin C-rich foods (like oranges) to improve absorption.
3. Omega-3 Fatty Acids – The Brain Food
Why kids need it:
Omega-3s (especially DHA) are vital for brain development, learning, and emotional regulation.
Signs of deficiency:
- Dry skin
- Trouble focusing
- Mood swings or hyperactivity
Why it’s common:
Most children don’t eat fatty fish (like salmon or mackerel) twice a week, which is the best source of omega-3s.
What to do:
Incorporate fish, chia seeds, or flaxseeds into meals, or consider a kids’ omega-3 supplement (vegan algae oil is a great option).
4. Calcium – The Bone Builder
Why kids need it:
Calcium strengthens bones, teeth, and supports muscle function.
Signs of deficiency:
- Weak bones or delayed growth
- Tooth decay
- Muscle cramps
Why it’s common:
Children who avoid dairy or fortified plant-based milks may not get enough calcium.
What to do:
Offer dairy or fortified plant milks, tofu, leafy greens, and yogurt.
5. B Vitamins – Energy and Mood Support
Why kids need them:
B vitamins (especially B12 and folate) help produce energy, support brain function, and maintain a healthy nervous system.
Signs of deficiency:
- Fatigue
- Poor appetite
- Mouth sores
- Irritability
Why it’s common:
Kids on plant-based diets may lack B12, which is found mostly in animal products.
What to do:
Add eggs, dairy, meat, or B12-fortified plant foods. A kids’ multivitamin with B12 is essential for vegan or vegetarian children.
Should You Give Your Kids a Multivitamin?
Even with a healthy diet, it’s tough to guarantee your child gets all the nutrients they need every single day. A clean, low sugar multivitamin can fill nutritional gaps and support your child’s immune system, energy, and growth.
At The Kids Vitamin Doctor, we create doctor-formulated, parent-approved vitamins with no artificial colours or sugars, and all the essential nutrients kids need.
Final Thoughts
The best way to prevent deficiencies is to focus on a balanced diet, but supplements can help fill in the gaps. If you’re unsure which vitamins your child needs, talk to your family doctor or paediatrician —and choose a high-quality kids’ vitamin you can trust.
