Jonathan Siekmann

• PhD
• Instructor at City College of San Francisco

Zinc could play a causal role in the etiology of anemia because of its many required functions in iron metabolism and immune health. Zinc deficiency and anemia often coexist, especially in low-income settings, where there are low intakes of iron and zinc, high intakes of phytates, and increased risk of inflammation. Although it is unknown to what d...

Background: Plasma or serum zinc concentration (PZC or SZC) is the primary measure of zinc status, but accurate sampling requires controlling for hemolysis to prevent leakage of zinc from erythrocytes. It is not established how much hemolysis can occur without changing PZC/SZC concentrations. Objective: This study determines a guideline for the lev...

Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. Cellular, tissue, and whole-body zinc homeostasis is tightly controlled to sustain metabolic functions over a wide range of zinc intakes, making it difficult to assess zinc insufficiency or excess. The BOND (Biomarkers of Nutrition for Development) Zinc...

The concept of a focused ethnographic study (FES) emerged as a new methodology to answer specific sets of questions that are required by agencies, policymakers, programme planners or by project implementation teams in order to make decisions about future actions with respect to social, public health or nutrition interventions, and for public-privat...

The present study examines the effect of animal-source-food (ASF) intake on arm muscle area growth as part of a larger study examining causal links between ASF intake, growth rate, physical activity, cognitive function and micronutrient status in Kenyan schoolchildren. This randomised, controlled feeding intervention study was designed with three i...

As a highly bioavailable iron compound, sodium iron (iii) ethylenediaminetetraacetate (NaFeEDTA) has been recommended as a food additive for fortification. The amount of a food additive that can be ingested daily over a lifetime without appreciable health risk is termed the acceptable daily intake (ADI). The ADI for NaFeEDTA is based on body weight...

The Codex Alimentarius is a collection of internationally recognized standards, codes of practice, guidelines, and other recommendations relating to foods, food production, and food safety. Among other functions, it is responsible for setting international standards for safety and hygiene. Codex food standards and guidelines directed at foods produ...

To compare the diagnostic performance of microscopy using Giemsa-stained thick and thin blood smears to a rapid malaria dipstick test (RDT) in detecting P. falciparum malaria in Kenyan school children. Randomised, controlled feeding intervention trial from 1998-2001. Rural Embu district, Kenya. The area is considered endemic for malaria, with four...

To construct growth curves for school-aged children and adolescents that accord with the WHO Child Growth Standards for preschool children and the body mass index (BMI) cut-offs for adults. Data from the 1977 National Center for Health Statistics (NCHS)/WHO growth reference (1-24 years) were merged with data from the under-fives growth standards' c...

The high prevalence of vitamin B-12 deficiency in many regions of the world is becoming recognized as a widespread public health problem, but it is not known to what extent this deficiency results from a low intake of the vitamin or from its malabsorption from food. In rural Kenya, where a previous study identified a high prevalence of inadequate v...

Animal source foods (ASF) can provide micronutrients in greater amounts and more bioavailable forms compared to plant source foods, but their intake is low in many poor populations. However, the impact of ASF on micronutrient status of undernourished populations has not been assessed. Supplemental meat (60-85 g/d), milk (200-250 mL/d) or energy (is...

Animal source foods (ASF) can provide micronutrients in greater amounts and more bioavailable forms compared to plant source foods, but their intake is low in many poor populations. However, the impact of ASF on micronutrient status of undernourished populations has not been assessed. Supplemental meat (60-85 g/d), milk (200-250 mL/d) or energy (is...

Undernutrition is widely perceived to affect the development of an effective immune system. We used a mini-analysis system to quantitate antibody titers and evaluate the sera of 200 Kenyan schoolchildren for antibodies to Helicobacter pylori [isotypes of immunoglobulins A (IgA), G (IgG), and M (IgM)], hepatitis A virus, rotavirus, tetanus toxoid (I...

Animal source foods (ASF) can provide micronutrients in greater amounts and more bioavailable forms compared to plant source foods, but their intake is low in many poor populations. However, the impact of ASF on micronutrient status of undernourished populations has not been assessed. Supplemental meat (60-85 g/d), milk (200-250 mL/d) or energy (is...

Degree granted in Nutrition. Thesis (Ph. D.)--University of California, Davis, 2001.