25-hydroxyvitamin-d-2 and Muscular-Diseases

Four cases of hypovitaminosis D were seen in a general practitioner's population in the Netherlands: a Somalian veiled woman aged 53 and her 11-year-old daughter, a dark-skinned Surinam woman aged 31, and a veiled Moroccan woman aged 56 years. This cause of myopathy has only been recently recognised and is more prevalent than often thought, especially in high-risk groups such as veiled and dark-skinned immigrants who lack sunlight in the Netherlands. Symptoms are muscle pain and mainly proximal muscle weakness resulting in difficulties in ascending a staircase or getting up out of a chair. The diagnosis is made on the basis of a detailed history and measurement of serum 25-hydroxyvitamin D. Calcium and serum alkaline phosphatase activity may be normal. Treatment with ergocalciferol is effective and cheap. As diagnosis and treatment are relatively simple, finding and treating hypovitaminosis D is a rewarding challenge to primary health care practitioners in the Netherlands.

Topics: 25-Hydroxyvitamin D 2; Adult; Child; Cultural Characteristics; Ergocalciferols; Female; Humans; Life Style; Middle Aged; Morocco; Muscle Weakness; Muscular Diseases; Netherlands; Pain; Risk Factors; Skin Pigmentation; Somalia; Suriname; Vitamin D Deficiency

Incidence of vitamin D deficiency is increasing worldwide. The purpose of this study was to determine if supplementation with vitamin D2 from Portobello mushroom powder would enhance skeletal muscle function and attenuate exercise-induced muscle damage in low vitamin D status high school athletes. Participants were randomised to Portobello mushroom powder (600 IU/d vitamin D2) or placebo for 6 weeks. Participants then completed a 1.5-h exercise session designed to induce skeletal muscle damage. Blood samples and measures of skeletal muscle function were taken pre-supplementation, post-supplementation/pre-exercise and post-exercise. Six weeks supplementation with vitamin D2 increased serum 25(OH)D2 by 9.9-fold and decreased serum 25(OH)D3 by 28%. Changes in skeletal muscle function and circulating markers of skeletal muscle damage did not differ between groups. In conclusion, 600 IU/d vitamin D2 increased 25(OH)D2 with a concomitant decrease in 25(OD)D3, with no effect on muscular function or exercise-induced muscle damage in high school athletes.

Topics: 25-Hydroxyvitamin D 2; Adolescent; Agaricus; Athletes; Biological Products; Calcifediol; Dietary Supplements; Exercise; Humans; Male; Muscle, Skeletal; Muscular Diseases; Schools; Sports; Vitamin D; Vitamin D Deficiency; Vitamins