Clinical Trial: Vitamin D, Iodine, and Lead Levels in Haitian Infants and Children.

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Vitamin D Deficiency, Iodine Deficiency and Lead Levels in Haitian Infants and Children.

Brief Summary:

Vitamin D deficiency is common worldwide, including in infants and children, and rickets remains a public health concern in many developing countries. The vitamin D status and prevalence of vitamin D deficiency in the Haitian population has not been studied. There is currently no approved point-of-care testing device for vitamin D deficiency. Iodine deficiency and resulting hypothyroidism is the leading cause of preventable neuro-developmental delay and cognitive impairment worldwide. Young infants and children are especially susceptible to sequelae of disruption in thyroid function given the dependence of the developing brain on sufficient levels of thyroid hormone. Perchlorate and thiocyanate have been described as potential environmental disrupters of thyroid function. Lead intoxication is a significant cause of disease throughout the world. Millions of people have suffered the effects of lead poisoning. Although most developed countries have taken drastic measures to limit the environmental lead levels, many countries in the developing world have not been able to address, or even assess, the problem.

Our objectives are to study the following three components in 300 Haitian children between 9 months and 6 years of age in three different geographical areas of Haiti: 1) Vitamin D status and prevalence of rickets, environmental factors associated with low vitamin D levels, and the accuracy and efficacy of a vitamin D point-of-care testing (POCT) device for the screening of vitamin D insufficiency. 2) Iodine status and thyroid function, and environmental disruptors such as perchlorate and thiocyanate as potential risk factors for abnormal thyroid function. 3) Lead levels and the extent of childhood lead poisoning.


Detailed Summary:

BACKGROUND:

  1. Vitamin D Deficiency

    Vitamin D deficiency is common in the United States and worldwide, including in infants and children 1,2. Moderate to severe deficiency in children can manifest as rickets, a skeletal disease which results from a failure of mineralization of developing bones and cartilage. In most industrialized countries, infantile vitamin D supplementation represents the standard of care and has lead to a dramatic reduction in the incidence of rickets. However, in many developing countries, rickets remains a public health problem 3.In addition, recent literature indicates that there may be a resurgence of rickets even in industrialized countries 4, especially among immigrant populations 5. Potential extraskeletal effects of vitamin D deficiency are also being increasingly recognized, including an increased susceptibility to type 1 diabetes, insulin resistance and the metabolic syndrome, pulmonary disease such as asthma, pneumonia and tuberculosis, and possible modulation of the innate immune system 6.

    Growing children with severe vitamin D deficiency, most commonly defined as serum 25-hydroxy-vitamin D (25OHD) levels less than 8 ng/ml, are at greatest risk for rickets and should undergo a diagnostic evaluation. When physical exam findings such as bowing of weight-bearing extremities, rachitic rosary, or frontal bossing are not evident, the level of serum alkaline phosphatase as an indicator for increased bone turnover and calcium mobilization from bone can be used as a screening test 4,7. X-rays of knees and wrists are typically obtained to confirm the diagnosis and establish a baseline for follow up.

    The vitamin D status and pre
    Sponsor: Boston Children’s Hospital

    Current Primary Outcome:

    • serum 25OHD levels [ Time Frame: Baseline ]
      Measure serum 25OHD levels, including the proportion of children found to be vitamin D insufficient, deficient and severely deficient.
    • urinary iodine levels [ Time Frame: Baseline ]
      Urinary iodine levels, including the proportion of children found to be iodine deficient
    • serum lead levels [ Time Frame: Baseline ]
      Serum lead levels in Haitian infants and children


    Original Primary Outcome: Same as current

    Current Secondary Outcome:

    • Number of children found to have elevated alkaline phosphatase levels [ Time Frame: Baseline ]
      The number of vitamin D deficient children found to have elevated alkaline phosphatase levels (as a proxy for vitamin D deficient rickets)
    • Dietary and sun exposure effect on vitamin D level [ Time Frame: Baseline ]
      to measure the influence of dietary vitamin D intake and sun exposure on vitamin D levels.
    • Determine the accuracy of the POCT device [ Time Frame: Baseline ]
      The 25OHD levels were measured via serum and POCT device to compare accuracy of the POCT device.
    • Goiter and abnormal thyroid function tests [ Time Frame: Baseline ]
      The number of children found to have goiters and/or abnormal thyroid function tests
    • Environmental disruptors of thyroid function [ Time Frame: Baseline ]
      Number of children with elevated levels of urinary perchlorate and/or thiocyanate
    • Lead intoxication [ Time Frame: Baseline ]
      Evaluation of the extent of childhood lead poisoning using the CDC definition of lead poisoning, (BLL) ≥ 10 µg/dL


    Original Secondary Outcome: Same as current

    Information By: Boston Children’s Hospital

    Dates:
    Date Received: November 23, 2014
    Date Started: January 2015
    Date Completion:
    Last Updated: June 23, 2015
    Last Verified: June 2015