To investigate the vitamin D status during winter of a healthy population of hospital employees and to assess the correlation between vitamin D status and risk of infections in the upper respiratory tract.

One hundred and ten healthy volunteers answered a questionnaire on their solar exposure habits and vitamin D intake and delivered one blood sample for quantification of vitamin D level (serum 25-hydroxyvitamin D (25(OH)D) concentration) during December 2007–January 2008. At the end of the winter we screened for the occurrence of respiratory infections and sought associations with vitamin D status.

Bucharest, Romania, 45°N.

One hundred and ten healthy hospital employees.

Eighty per cent of participants were vitamin D deficient (25(OH)D level below 50 nmol/l). The main determinant of serum 25(OH)D was sun exposure during the summer previous to the study (P = 0·02 in multivariate analysis). Intake of vitamin D, BMI and age played no significant role for the level of 25(OH)D. Overall we found a non-significant negative correlation between 25(OH)D level and new cases of infection (Spearman correlation coefficient of −0·12, P = 0·2).

Vitamin D status is alarmingly poor in active, relatively young women residing in Romania. If our results are reproduced by other investigations, action to improve vitamin D status at the population level is necessary. We were not able to show a statistically significant relationship between vitamin D status and infection risk in our material.

To review the health effects of solar radiation, sunbeds and vitamin D.

The literature was searched in the electronic database MEDLINE to indentify published data between 1981 and 2011. Studies were included if they reported relative risk for cutaneous malignant melanoma (CMM) associated with sunbed use, vitamin D and UV effects on human health.

Data from different time periods for populations at different latitudes.

Persons of different ages and ethnic groups.

UV from sun and sunbeds is the main vitamin D source. Young people with white or pigmented skin in northern Europe have a low vitamin D status. A number of health benefits from sufficient levels of vitamin D have been identified. However, UV exposure has been suspected of causing skin cancer, notably CMM, and authorities warn against it.

The overall health benefit of an improved vitamin D status may be more important than the possibly increased CMM risk resulting from carefully increasing UV exposure. Important scientific facts behind this judgement are given.