Vitamine D Deficiency Among Ethnic Populations in the Northern Countries

1. Vitamine D Deficiency Among Ethnic Populations in the Northern Countries By ÅsmundToresen

2. Vitamin D • Group of fat-soluble prohormones with two main groups: D2 – Ergocalciferol from plants D3 – Cholecalciferol from animals • In our skin: D3 is formed from 7-dehydrocholesterol with help of UV-radiation • Liver: 25-hydroxycholecalciferol • Kidney: 1,25-dihydroxycholecalciferol – active form • Regulated in kidney by PTH and hypophosphatemia

3. Role of Vitamin D • Promote absorption of calcium and phosphate in the intestine and reabsorption of calcium in the kidneys, enabling normal mineralization of bone and preventing hypocalcemictetany. • Necessary in bone growth and remodeling. • Also inhibit PTH secretion from the parathyroid gland, modulate neuromuscular and immune function and reduce inflammation.

5. Deficiency can lead to: • In children: Rickets, it is a softening of bones in children potentially leading to fractures and deformity. • Adults: Osteomalacia, a softening of the bones due to defective bone mineralization. It may show clinical signs such as diffuse body pains, muscle weakness, and fragility of the bones. • Might contribute to development of osteoporosis, research is done on the preventative effects of Vitamin D • Maternal vitamin D deficiency early in pregnancy is a strong, independent risk factor for preeclampsia

6. Deficiency is defined as levels less than 20 mg per ml of 25-hydroxy vitamin D. • Levels between 20 to 30 indicate insufficiency and anything above 30 is considered normal.   • Toxic levels are over 150 mg per ml and are exceedingly rare. • Cases of vitamin D toxicity with hypercalcemia have involved intake of over 1,000 micrograms/day (40,000 IU)

8. Dietary sources • Very few food sources contain vitamin D. Oily fish such as salmon, sardines, mackerel, and tuna along with egg yolks, and fish liver oils. • In many countries, such foods as milk, yoghurt, margarine, oil spreads, breakfast cereal, pastries and bread are fortified with vitamin D2 and/or vitamin D3 to minimize the risk of vitamin D deficiency.

9. Nutritional need • Recommended minimal daily intake: 400 IU (10micrograms) • Safe upper limit is at 2000 IU • A glass of milk supplemented with Vit D is 100IU • 1 Tbs of cod liver oil 15ml contain almost 1360 IU • Normally a healthy diet containing fish and milk should be sufficient.

11. Known risk-factors • Migration to northern latitudes • Winter climate • Staying indoors and in the shade • Clothing, covering of skin • Melanin pigmentation (dark skin) • Diet poor in vitamin D containing foods • Prolonged exclusive breastfeeding

12. Occurrence in Norway • A very high prevalence of vitamin D deficiency has been observed among pregnant and delivering women with Pakistani background living in Oslo. • Among healthy adult men and women born in Pakistan, Sri Lanka, Turkey, Iran, and Vietnam 37% had vitamin D deficiency, and 90% had vitamin D insufficiency

13. A study performed in Kandy (Sri Lanka) and Oslo showed that Tamil Sri Lankans who had immigrated to Oslo had 9 times higher prevalence of vitamin D deficiency than those living in their country of origin . • Six weeks old infants and their mothers with Pakistani, Turkish, and Somali background who attended child health clinics in Oslo had a high prevalence of vitamin D deficiency

14. Intervention • Ethnic tailored dietary advice should be made • Vitamin D should be added to all types of milk, also whole milk • Non-western immigrants should be encouraged to take vitamin D supplements throughout the year. This is of particular importance for pregnant women, infants and children.

15. Sources • http://mighealth.net/no/index.php/Vitamin_D_deficiency • http://www.prlog.org/10296977-vitamin-deficiency-resurfacing-worldwide-pregnant-women-at-risk.html • Wikipedia as usual…