Table 1.

Full search strategies for all databases.

Database	Search strategy	Filters/Limits
PubMed	(“child*” OR “infant*” OR “toddler*” OR “preschool*”) AND (“malnutrition” OR “undernutrition” OR “stunting” OR “wasting” OR “underweight”) AND (“rickets” OR “vitamin D deficiency” OR “calcium deficiency”) AND (“anemia” OR “iron deficiency” OR “hemoglobin” OR “hematologic disorders”)	Humans, all languages, from inception to Dec 2025
Embase	(‘child’/exp. OR ‘infant’/exp. OR child* OR infant* OR toddler*) AND (‘malnutrition’/exp. OR ‘undernutrition’/exp. OR malnutrition OR undernutrition OR stunting OR wasting OR underweight) AND (‘rickets’/exp. OR rickets OR ‘vitamin D deficiency’ OR ‘calcium deficiency’) AND (‘anemia’/exp. OR anemia OR ‘iron deficiency’ OR hemoglobin)	Human studies, all years, all languages
Web of Science	TS = (child* OR infant* OR toddler* OR preschool*) AND TS = (malnutrition OR undernutrition OR stunting OR wasting OR underweight) AND TS = (rickets OR “vitamin D deficiency” OR “calcium deficiency”) AND TS = (anemia OR “iron deficiency” OR hemoglobin)	All document types, no language restrictions
Cochrane Library	(“child*” OR “infant*” OR “toddler*”) AND (“malnutrition” OR “stunting” OR “wasting” OR “underweight”) AND (“rickets” OR “vitamin D deficiency” OR “calcium deficiency”) AND (“anemia” OR “iron deficiency”)	Cochrane reviews and trials, all years
Google Scholar	“child*” OR “infant*” OR “toddler*” AND malnutrition OR undernutrition OR stunting OR wasting OR underweight AND rickets OR “vitamin D deficiency” OR “calcium deficiency” AND anemia OR “iron deficiency”	First 200 results per search, all years, all languages