Vitamin D2, Muscle Damage, NASCAR Pitcrew
Condition: Muscle Function; Muscle Soreness; Vitamin D Status
MeSH terms: Myalgia
Study type: Interventional

Summary: 
      Hypothesis: Six weeks of supplementation with vitamin D (4000 IU/day) using Dole's Vitamin D
      Portobello Mushroom Powder will increase winter serum vitamin D levels, and improve muscle
      function and strength, and innate immunity (granulocyte/monocyte phagocytosis and oxidative
      burst activity), and attenuate exercise-induced muscle damage and DOMS.
    

Detailed description: 
      Vitamin D2 is found naturally in sun-exposed mushrooms, and vitamin D3 is synthesized in the
      skin when exposed to sunlight and is present in oil-rich fish such as salmon, mackerel, and
      herring. Mushrooms contain very little or any vitamin D2 but are abundant in ergosterol,
      which can be converted into vitamin D2 by ultraviolet (UV) illumination (Eur J Clin Nutr.
      2011;65:965-71).

      In recent decades, there has been increased awareness of the impact of vitamin D on muscle
      function (Scand J Med Sci Sports. 2010;20:182-90). In the early 20th century, athletes and
      coaches felt that ultraviolet rays had a positive impact on athletic performance, and
      evidence is accumulating to support this view. Both cross-sectional and longitudinal studies
      support a functional role for vitamin D in muscle, and the discovery of the vitamin D
      receptor in muscle tissue provides a mechanistic pathway for understanding the role of
      vitamin D within muscle. Studies in athletes have found that vitamin D status is variable and
      is dependent on outdoor training time (during peak sunlight), skin color, and geographic
      location (Pediatr Clin North Am. 2010;57:849-61).

      25(OH)D is the best indicator and major form of vitamin D in the blood, with a circulating
      half-life of 2-3 weeks. Vitamin D deficiency is defined as a plasma vitamin D [25(OH)D] level
      of less than 20 ng/ml, with vitamin D insufficiency defined as 21-29 ng/ml. Estimates are
      that 20-100% of children, young and middle-aged adults, and community-dwelling elderly men
      and women are vitamin D deficient (J Clin Endocrinol Metab. 2011;96:1911-30).

      Purpose: To determine if 6 weeks supplementation with Dole Vitamin D Portobello Mushroom
      Powder (4,000 IU/day) can, 1) increase winter serum vitamin D levels, and measure whether
      vitamin D supplementation 2) has a chronic influence on muscle function and strength, and
      innate immune function, and 3) can attenuate exercise-induced muscle damage and delayed onset
      of muscle soreness (DOMS) in athletes.
    

Intervention name(s): Vitamin D2 mushroom powder; Placebo
Intervention type(s): Dietary Supplement; Other
Intervention description(s): Subjects will be given Portobello mushroom powder with or without vitamin D mixed in soymilk powder in six plastic containers (one for each week of the study). Subjects will ingest one level teaspoon of the product each day (with or without 4,000 IU vitamin D2) and consume during breakfast in one of the following ways: mixed in water, juice, yogurt, or milk.; Mushroom powder without vitamin D2
Other intervention name(s): UV radiated Portobello mushroom powder
Intervention MeSH terms: Vitamin D; Ergocalciferols
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: Strength; Anaerobic power; Muscle soreness; Immune function