Lecture 18 Flashcards
What trace elements are low in NZ soil?
- Fluoride
- Selenium
- Iodine
What are the strategies for increasing dietary intake in NZ?
- Fortification - adding to staple foods e.g. bread
- Supplementation - good for target groups e.g. pregnant women, as people aren’t very compliant
- Dietary Diversification - works for individuals with simple diets e.g. African. This technique DOES NOT WORK IN NZ
What are the functions of Iodine?
- Key part of thyroid hormones (T4 and T3)
- Maintains metabolic rate
- Needed for growth and development
Why does a goitre form?
-Enlarges to try capture more iodine as a consequence of low iodine levels
What are the dietary sources of Iodine?
- Rich sources
- >fish/seafood
- >iodised salt - Moderate source
- >eggs
- >milk/milk products
- >fortified bread - Poor Sources
- >fruit and vege
Describe the absorption of Iodine
100% absorbed, not regulated
What % of iodine is excreted in the urine?
90%
Are there any iodine stores in the body?
- No stores
- Thyroid hormones can be stored for up to 3 months
How is iodine status assessed?
- Median urinary iodine concentration
- Thyroid volume : goitre rate (<5%)
- Thyroid hormones T3/4/g
Describe the deficiency history in NZ
1911-30’s = mild-moderate IDD
- > low urinary iodine
- > up to 30% of children with goitre
- > no reports of cretinism
1940’s = iodised salt
1950’s = goitres become infrequent
1960’s = (at this point levels were sufficient) introduction of iodophors
1990’s = deficiency
What are the reasons for re-emergence of deficiency?
- Fast food intake increasing which doesn’t use iodised salt
- Health recommendation to decrease salt
- Dairy industry stopped using iodophors
- Rock and sea salt used (not iodised salt)
What improvement methods were implemented to increase iodine levels?
- Supplementation = pregnant and lactating women recommended a tablet
- Fortification = mandatory use of iodised salt for bread making
What symptoms are seem at mild deficiency?
People with a goitre
What symptoms are seem between mils and moderate deficiency?
Impaired mental and motor abilities
What symptoms are seem at moderate deficiency?
Hypothyroidism
What symptoms are seem at severe deficiency?
Cretinism
->when an iodine deficient mother has a child
