The present study characterized the prevalence and seasonal variation of vitamin D (Vit D) deficiency/insufficiency in healthy children and adolescents in Greece and explored its relationship with sunscreens. 

It measured the serum level of 25-hydroxyvitamin D (25[OH]D) in 376 children and adolescents (184 males and 192 females) with a mean age of 7.6 ± 4.9 years at different time points over 13 months. 

The study observed:

• 66.2% prevalence of low serum 25(OH)D level, including deficiency and insufficiency.
• The lowest mean 25(OH)D in January (17.9 ± 6.8 ng/mL) and the highest in September, July, August and October (34.6 ± 8.7, 33.0 ± 9.4, 30.1 ± 8.2 and 30.1 ± 10.6 ng/mL, respectively).
• Higher levels of serum 25(OH)D in the children who applied sunscreens on the beach or off the beach.
• The subjects with deficiency and insufficiency were significantly older than those with normal levels of 25(OH)D; however, there wasnt any significant difference according to gender. 

This study highlights the high prevalence of low serum levels of 25(OH)D and their seasonal variation in children living in a region characterized by many hours of sunshine. These data suggest that the real-life use of sunscreens during the summer months permits the absorption of sufficient sunlight to enable the production of Vit D at a level adequate to maintain normal serum levels. The health care provider should give Vit D supplements to children during the months of lower sun exposure.

Source: Feketea GM, Bocsan IC, Tsiros G, et al. Vitamin D status in children in Greece and its relationship with sunscreen application. Children (Basel). 2021;8(2):111.