Nutritional Deficiencies in Children During Cancer Treatment

When your child is going through cancer treatment, food becomes a daily source of worry. Every meal brings questions: are they eating enough, are they getting what their body needs, will this help or harm them? These concerns are shared by nearly every parent walking this path.

Why deficiencies develop

Cancer treatment places intense demands on a child’s body. Chemotherapy, radiation, and steroids increase nutritional needs while making eating harder. Nausea, vomiting, mouth sores, taste changes, diarrhea, constipation, and fatigue can all reduce intake. Even when children manage to eat, their bodies may struggle to absorb nutrients properly.

Nutrients commonly affected

There is a deficiency of vitamin D, vitamin C, vitamin A, vitamin B-complex, iron, zinc, selenium, potassium, and magnesium in many children. Vitamin D is essential for bone strength and immunity, but low consumption is widespread because of the deprivation of sunlight and steroid intake. Anaemia and exhaustion may result from iron deficiency. The deficiency of zinc and vitamin C impairs the immune system and slows down the healing process. These are the losses that occur behind the scenes yet have tangible results.

Eating challenges parents recognize

Taste preferences tend to shift rapidly. Something that the child once liked might be metallic or bitter. Protein may be rejected. Fruits and vegetables might be intolerable. Sweet snacks are so easy to access that parents are left indecisive between healthy food and just getting food on board. This is not a failure in parenting—this is a side effect of treatment.

How poor nutrition affects recovery

Nutritional deficiencies can reduce tolerance to treatment, increase infections, delay healing, and contribute to fatigue. Some children lose muscle even when their weight stays the same. Growth may slow, and recovery after treatment can take longer. These effects add strain to an already difficult journey.

Support that makes a difference

Nutrition during cancer treatment requires planning and support. Pediatric oncology dietitians help tailor high-protein, high-calorie meal plans that meet increased needs. Nutritional supplements and prescribed vitamins or minerals are often essential, not optional. Medications to reduce nausea or stimulate appetite can improve intake. In some cases, feeding tubes are needed to protect a child from severe malnutrition. While emotionally difficult, this step can stabilize nutrition and allow treatment to continue safely.

You are not failing

If you are struggling with your child’s nutrition, then you are not alone. Nutrition is part of cancer treatment, and asking for help early is an act of care, not fear. Cancer takes enough from a child’s body. Supporting nutrition is one way parents help give strength back steadily, patiently, one day at a time.