Iodine Deficiency Flashcards
What gland in the human body uses iodine?
Thyroid gland
What do thyroid hormones do?
Help control growth, repair damaged cells, support healthy metabolism
People at risk for iodine deficiency include:
- Pregnant women
- Ppl in countries with little iodine in soil
- Ppl who don’t use iodized salt
- Vegetarians or vegans
Symptoms of iodine deficiency include:
- Swelling in neck
- Weight gain
- Fatigue and weakness
- Hair loss
- Dry flaky skin
- Feeling cold
- Slowing of heart rate
- Trouble learning and remembering
- Pregnancy complications
- Heavy/irregular periods
How much iodine do adults need per day?
150mcg/day
Iodine deficiency can cause
hypothyroidism, a condition in which the body can’t make enough thyroid hormones
What is one way to prevent iodine deficiency?
Add iodized salt to meals
Only need very small amounts of iodine for good health. Without iodine, your health can be affected over the long term.
Body doesn’t make iodine so it must come from diet
Iodine is added to all table salt in
Canada (1tsp contains 380mcg of iodine)
- Kosher, pickling, and sea salt are a source of natural iodine but do not contain as much as iodized table salt
30% of the world is at risk for iodine deficiency and
insufficient intake is the most common cause of preventable mental retardation and brain damage
What are 7 foods rich in iodine?
1) Sea vegetables (kelp, seaweed, etc)
2) Cranberries
3) Yogurt
4) Organic navy beans
5) Organic strawberries
6) Himalayan crystal salt (pink salt)
7) Potatoes
> 70 countries, including USA and Canada, have salt iodization programs. As a result,
~70% of households worldwise use iodized salt, ranging from almost 90% in North and South America to less than 50% in Europe, parts of Asia and the Eastern Mediterranean
The majority of salt intake in the USA comes from
processed foods, however food manufacturers almost always use non-iodized salt in processed foods
If a person’s iodine intake falls below ~10-20mcg/day, hypothyroidism occurs
a condition that is usually accompanied by goiter
- Goiter is usually the earliest clinical sign of iodine deficiency
- In pregnant women, iodine deficiency of this magnitude can cause major neurodevelopmental deficits and growth retardation in the fetus, as well as miscarriage and stillbirth
Iodine during fetal development
- For women living in countries with weak, sporadic, or uneven iodized salt distribution, the WHO recommends iodine supplementation for all women of childbearing age
- Only 51% of the types of prenatal multivitamin marketed in USA contain iodine
- In USA and Canada, the American Thyroid Association recommends iodine supplementation as part of a prenatal vitamin/mineral supplement for pregnant and lactating women
Cretinism (now known as Congenital Iodine Deficiency Syndrome)
- Chronic, severe iodine deficiency in utero causes cretinism
- Characterized by mental retardation, deaf mutism, motor spasticity, stunted growth, delayed sexual maturation, and other physical and neurological abnormalities
Health effects in infants and children
- Iodine deficiency in childhood can also cause neurodevelopmental deficits such as a somewhat lower-than-average intelligence (IQ), studies show a decrease of 12-13pts
- Mild to moderate maternal iodine deficiency has been associated with an increased risk for ADHD in children
- Studies have shown that iodine supplementation in children living in areas of iodine deficiency positively affects physical and mental development, including reasoning skills
Geological Distribution of iodine in soils
- Mountainous areas and river valleys are prone to flooding, esp in South and SE Asia, are among the most iodine-deficient regions in the world
- Rain contributes iodine (evaporated from oceans) to soil
- Frequent flooding or snow melt leaches iodine from the soil
- Iodine-deficient soils produce crops that have low iodine lvls
- Populations in these areas are at risk of iodine deficiency unless they have access to iodized salt or foods produced outside the iodine-deficient area
Congenital Iodine Deficiency in Europe
- Common in areas of southern Europe around the Alps
- Earliest Alpine mountain climbers sometimes came upon whole villages with it
- Prior to 20th century, the cause was not known and it was often attributed to “stagnant air” in mountain valleys or “bad water”
- Severe cases were a minority, and most ppl were only affected to the extent of having a goiter and some degree of reduced cognition and growth
- Most ppl were able to function in their society
- These areas were referred to as “goiter belts”
- Switzerland (soil doesn’t contain much iodine) had many iodine deficiency syndrome cases
Iodine Deficiency, an example from Sir Lanka
- Goiter is est to affect 10mil people in Sri Lanka
- Partially successful iodized salt program has been introduced
Study: soil and rice sampled collected from 15 villages in Sri Lanka
Results: total iodine concentrations in soils were the same in highly iodine deficient villages as in less iodine deficient
- However, they found in highly deficient areas the iodine was absorbed onto oxide minerals and organic matter in the soils, making it unavailable for plants
- Found rice doesn’t uptake iodine very well and green leafy vegetables are better
- Unfortunately, rice is a much bigger part of the local diet than green leafy vegetables
