Plenty of information is available on the links between vitamin D and health. Studies indicate that fat soluble vitamin D produces health benefits, especially by preventing falls and fractures. Lack of vitamin D leads to rickets in children and osteoporosis in adults.
Vitamin D is produced in the skin between March and October, with the highest quantities being produced in the summer months. The intake of vitamin D both through the skin and from dietary sources is described as the vitamin D level in the blood, or serum 25(OH)D concentration. A concentration exceeding 50 nmol/l is considered adequate for health reasons. Research indicates that people who spend average amounts of time outdoors in the summer months need to get about 10 µg/day of vitamin D from their diet or as a dietary supplement through the year to ensure an adequate level of serum 25(OH)D concentration. Older people, and also younger people who spend little time outdoors, should get up to 20 µg/day of vitamin D to reach the target serum concentration level.
A daily vitamin D supplement is recommended all year round for all those living in Finland who are pregnant, breastfeeding or aged under 18 years, and those who do not use vitamin D fortified products or fish regularly.