Vitamin D and its importance for children

It may be known to you as the “vitamin of the sun” since it is composed on our skin after sun exposure. In this way, our body is actually covering its needs to a greater percentage compared to diet. What is certain is that vitamin D plays a crucial role in the absorption of calcium which is in turn associated with healthy bone and skeletal growth.

What are the implications of low vitamin D levels?

Vitamin D deficiency is associated with rickets, a disease which results in soft bones and skeletal deformities, since it is another development stage for them. But while scientists keep discovering new functions for vitamin D, from its hormonal function to its support to the immune system, apart from rickets, vitamin D deficiency is all the more linked with more chronic health problems such as heart-related diseases, multiple sclerosis, diabetes, thyroid disorders etc.

Hypovitaminosis for children in Greece too? Possibly yes…

While for Northern Europe, where sunlight is less, things are more clear and the supplementary use of vitamin D is systematic and compulsory, evidence for Southern Europe are not as obvious as you would expect. Recently, a big meta-analysis of 107 studies pertaining to the levels of vitamin D showed that there is a large percentage of lack of vitamin D in the countries of Southern Europe and the Eastern Mediterranean.

By focusing on children in Greece, a recent study showed that the percentage of school-age students with low vitamin D levels reached 52% at the end of the winter season. The problem seemed to be bigger in urban areas compared to rural areas. This is due to the tall city buildings in the shade of which we have to spend a lot of time during the day, even we are outside, but also air pollution in the cities which seems that prevents UVB radiation from reaching our skin and start the composition of vitamin D.

How can you ensure higher levels of vitamin D for your child?

As the dietary sources of vitamin D are little, including oily fish (e.g. herring, sardines, salmon), egg yolk and dairy, and vitamin D concentration in these foods is low, the best natural source is the exposure to sunlight. For the composition of the vitamin on our skin, 15-20 minutes of hand, chest or face exposure to the sun without the use of sunscreen are enough. During the summer, exposure to sunlight without sunscreen must be restricted to early morning hours or evening hours in order to avoid strong and dangerous radiation.

Alternatively, and mainly complementary to sunlight exposure, it would be good for your children as well as yourselves to choose foods or dairy fortified with vitamin D or a supplement. Also remember that this is a fat-soluble vitamin which means that in order to be absorbed, it must be consumed together with a food that contains even a small amount of fat. This makes dairy products that are fortified with vitamin D, even their light versions, the ideal sources for vitamin D intake.

Indicative bibliography

Manios Y, Moschonis G, Hulshof T, Bourhis AS, Hull GLJ, Dowling KG, Kiely ME, Cashman KD. Prevalence of vitamin D deficiency and insufficiency among schoolchildren in Greece: the role of sex, degree of urbanisation and seasonality. Br J Nutr. 2017 Oct;118(7):550-558.
Manios Y, Moschonis G, Lambrinou CP, Tsoutsoulopoulou K, Binou P3, Karachaliou A, Breidenassel C, Gonzalez-Gross M, Kiely M, Cashman KD5. A systematic review of vitamin D status in southern European countries. Eur J Nutr. 2018 Sep;57(6):2001-2036.
Institute of Preventive Medicine, Environmental and Occupational Health Prolepsis, Greek National Dietary Guidelines for Infants, Children and Adolescents
https://www.webmd.com/vitamins/ai/ingredientmono-929/vitamin-d