The effect of dietary iron intake on the development of iron overload among homozygotes for haemochromatosis.
OBJECTIVE
To quantify the role of dietary Fe in total body Fe (TBI) accumulation among homozygotes for the HFE gene associated with haemochromatosis.


METHODS
A Monte Carlo model was built to simulate Fe accumulation based on findings from human feeding experiments and national dietary surveys. A hypothetical cohort of 1000 homozygotes with starting age 25 years was used in 39-year simulations. The impact of reducing dietary Fe intake on Fe accumulation was tested.


RESULTS
In the baseline model without any dietary intervention, by age 64, the percentage of males with TBI > 10 g, >15 g and >20 g was 93.2%, 49.6% and 14.7%, respectively. When the Fe intake of individuals in the cohort was reduced to < or =200% of the recommended dietary allowance (RDA), the corresponding percentages were 92.0%, 40.5% and 10.2%, respectively. The corresponding figures were 91.0%, 40.0% and 9.3% for Fe defortification and 70.3%, 21.3% and 4.1% when Fe intake was capped at 100% RDA. Similar trends were seen with sexes combined, although the impact of interventions was less. Sensitivity analysis revealed that the rate of Fe accumulation and the impact of dietary interventions are highly dependent on assumptions concerning Fe absorption rates.


CONCLUSIONS
Variation in Fe intake as currently observed in the USA contributes to variation in Fe accumulation among homozygotes, when continued over an extended period. Lifelong dietary habits and national fortification policy can affect the rate of Fe accumulation, although the magnitude of the effect varies by gender, the TBI level of interest and factors affecting the Fe absorption rate.
Tao
Min
M
Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA.
Pelletier
David L
DL
D000328:Adult; D004034:Diet Surveys; D004305:Dose-Response Relationship, Drug; D005260:Female; D006432:Hemochromatosis / Q000235:genetics / Q000378:metabolism*; D006720:Homozygote; D006801:Humans; D007408:Intestinal Absorption; D007501:Iron / Q000378:metabolism*; D019266:Iron, Dietary / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009010:Monte Carlo Method; D012737:Sex Factors; D014481:United States
D019266:Iron, Dietary; D007501:Iron