Vitamin D intake is low and hypovitaminosis D common in healthy 9- to 15-year-old Finnish girls.
Lehtonen-Veromaa M, Möttönen T, Irjala K, Kärkkäinen M, Lamberg-Allardt C, Hakola P, Viikari J.
Eur J Clin Nutr. 1999 Sep;53(9):746-51.
PMID: 10509773
CONCLUSION: Hypovitaminosis D is fairly common in growing Finnish girls in the wintertime, and three months of vitamin D supplementation with 10 microg/d was insufficient in preventing hypovitaminosis D. The daily dietary vitamin D intake was insufficient (< 5 microg/d) in the majority of participants, while the calcium intake was usually sufficient.