Vitamin D deficiency at the A rctic C ircle – a study in food‐allergic adolescents and controls

Aim At the extremes of latitude, UVB intensity is insufficient for adequate vitamin D synthesis in winter. Fatty fish, vitamin D enriched milk, margarine and eggs are main dietary sources of vitamin D . Their elimination may increase the risk of vitamin D deficiency. The aim was to assess vitamin D status in food‐allergic adolescents eliminating milk, egg and/or fish compared with adolescents on normal diets. Methods In winter, vitamin D intake was assessed by a food frequency questionnaire in 20 food‐allergic adolescents and 42 controls in the population‐based O bstructive L ung D isease I n N orthern S weden ( OLIN ) cohort studies. Vitamin D supplementation was queried. S erum 25‐hydroxyvitamin D [ S ‐25( OH ) D ] and S ‐parathormone ( S ‐ PTH ) levels were determined. Results Mean ( SD ) dietary vitamin D intake was 7.9 (3.6) μg/day in allergic adolescents and 7.8 (3.4) in controls (p > 0.05). Mean ( SD ) S ‐25( OH ) D levels in supplement consumers were 44 (18) nmol/L compared with 35 (10) in non‐consumers (p = 0.03). S ‐25( OH ) D and S ‐ PTH levels were similar in food‐allergic adolescents and controls (p > 0.05). Eighty‐two percentage had deficient S ‐25( OH ) D levels <50 nmol/L, and none reached levels >75 nmol/L. Conclusion Vitamin D deficiency was as common in food‐allergic adolescents as in controls although the vitamin D intake met national recommendations. Large‐scale studies on the prevalence of vitamin D deficiency in this region are needed.