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OpenTrials
Completed

NCT Number: NCT01208636

Environmental & Genetic Influences on Vitamin D Status

The purpose of this study is to determine the effect of environmental and genetic influences on Vitamin D status.

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Key information

Conditions

Vitamin D Deficiency Avitaminosis Deficiency Diseases Malnutrition Nutrition Disorders Nutritional and Metabolic Diseases

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Creighton University

Omaha, Nebraska, 68131, United States

About this study

Vitamin D deficiency is a common problem. The principal source of vitamin D for humans is solar exposure, with cutaneous synthesis of vitamin D by photoconversion of 7-dehydrocholesterol in the skin to pre-vitamin D3. Latitude, altitude, season, skin pigmentation, and age are recognized factors that influence how much vitamin D can be made by solar exposure. Surprisingly, Vitamin D deficiency has been described in people dwelling in southern Florida and in surfers in Hawaii. We hypothesize that genetic variations in vitamin metabolism accounts for these differences.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Able to consent and come for a study visit.
  • Male or female between ages 18-60.
  • Sun exposure >3 hours daily for at least 5 days weekly for the last 3 months.

Exclusion criteria

  • Unable to consent or come to a visit
  • Taking Vitamin D supplements, anticonvulsants, barbiturates, steroids, having granulomatous disease, or liver or kidney disease as these medications and conditions interfere with Vitamin D metabolism.
  • Related to another participant by blood.

Treatment and study plan

Primary outcomes

  1. 25(OH)D levels

    Time frame: 1 month

    25(OH)D levels were measured at the only visit

Secondary outcomes

  1. Genetic testing of 13 candidate genes

    Time frame: 1 month

    13 candidate genes were tested and their relationship to 25(OH)D examined.

Sponsors and collaborators

Lead sponsor

Creighton University

Other

Collaborators

  • Procter and Gamble

Registry information

Important dates

Study start
2010
Primary completion
2010
Study completion
2010
First posted
Sep 24, 2010
Registry last updated
Sep 24, 2010

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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