Vitamin D Deficiency in Children: What You Should Know

Vitamin D deficiency in children is related to many causes, such as lack of sunlight, and it may lead to rickets, among other diseases.
Vitamin D Deficiency in Children: What You Should Know

Last update: 08 December, 2020

Vitamin D deficiency in children can be caused by several factors. Different studies have found that low serum vitamin D concentrations may be related to extraosseous diseases. Thus, it’s important to maintain healthy levels of vitamin D in children. In this article, you’ll find out what happens when there’s vitamin D deficiency in children and how to prevent it.

Vitamin D deficiency in children

Vitamin D is a prohormone that promotes intestinal efficacy of calcium absorption. However, its deficiency may relate to rickets in children and osteomalacia in adults.

Rickets occur when there’s a lack of mineralization of the bone and of the growth cartilage. In recent decades, there have been many cases of rickets, due to vitamin D deficiency.

In the case of children, vitamin D deficiency is 25(OH)-D serum 37.5 nmol/l, and higher than 50 nmol/l is considered enough.

Causes of vitamin D deficiency

Reduction of vitamin D synthesis

Vitamin D synthesis occurs mainly by sunlight exposure. In Northern Europe and North America, rickets, related to vitamin D deficiency, are associated with:

  • Dark skinned children, who follow strict vegetarian, cultural or trendy diets.
  • Dark sinned breastfed babies between 3 to 6 months old.
  • Premature babies.
  • Children whose mother are deficient in vitamin D.
Vitamin D Deficiency in Children: What You Should Know

Excessive use of sunscreen may also affect skin synthesis of vitamin D.


The third trimester is the most relevant in relation to bone mineral density. Therefore, vitamin D deficiency may lead to bone alterations during that period. The ESPGHAN recommends from 800 to 1000 IU vitamin D supplies per day.


Evidence from prepubescents shows a relation between serum concentrations of vitamin D and adiposity. Because of its fat-soluble nature, vitamin D may store in the adipose tissue. Thus, obese children might require higher doses of vitamin D.

Malabsorption syndromes

Malabsorption syndromes may lead to deficiency in vitamin D. Among these syndromes, we can find:

Many factors may cause this deficiency, like lower fat-soluble vitamin absorption and hypocalcemia.


Cases of children deficient in vitamin D relate to bronchial asthma and asthma exacerbations, which lead to corticosteroids therapy.

Cardiovascular diseases  

In observational studies, children deficient in vitamin D had a 2.5 higher risk of high blood sugar level, and 2.4 higher risk of blood pressure. In addition to that, children deficient in vitamin D are at 4 times greater risk of developing metabolic syndrome.

Vitamin D Deficiency in Children: What You Should Know

How to prevent vitamin D deficiency

As mentioned before, vitamin D synthesis occurs by sunlight exposure. This is why sunlight exposure to the dorsal part of the body, increases rapidly 25(OH)D concentration levels in plasma.

In fact, children should be exposed to sunlight for just 15 minutes, three times a week. However, if exposure isn’t possible, because of lack of outdoor activities, weather conditions, etc., it’s important to administer this vitamin orally.

Nevertheless, not many foods have the necessary amount of vitamin D. In addition, this amount will vary according to the food preparation. For example, when frying fish, vitamin D decreases 50%. Fortified food could be an option, or 400IU/day administration, during the first year of life.

In case of deficiency, vitamin D supplements are recommended for the clinical disorders mentioned above. Doses between 400 and 1000IU could be enough.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Cediel, G., Corvalán, C., López de Romaña, D., Mericq, V., & Uauy, R. (2016). Prepubertal Adiposity, Vitamin D Status, and Insulin Resistance. Pediatrics, 138(1), e20160076. doi:10.1542/peds.2016-0076
  • Cediel, G., Pacheco-Acosta, J., & CastiUo-Durdn, C. (2018). Deficiencia de vitamina D en la práctica clínica pediátrica. Archivos argentinos de pediatría116(1), e75-e81.
  • Hossein-nezhad, A., & Holick, M. F. (2013). Vitamin D for health: a global perspective. Mayo Clinic proceedings, 88(7), 720–755. doi:10.1016/j.mayocp.2013.05.011
  • Mengual Gil JM. (2018). Vitamina D por encima del año de vida, ¿es necesaria o está de moda? En: AEPap (ed.). Curso de Actualización Pediatría 2018. Madrid: Lúa Ediciones 3.0; 2018. p. 17-30.
  • Misra, M., Pacaud, D., & Petryk, A. (2008). Deficiencia de vitamina D en los niños y su tratamiento: revisión del conocimiento y las recomendaciones actuales. Pediatrics66(2), 86-106.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.