An increasing number of young women risk giving birth to babies with an insufficiently developed mental capacity due to iodine deficiency. The deficiency may be a result of nutrient-depleted soil and altered diets with fewer iodine-containing animal sources. Also, many people have a preference for sea salt and Himalayan salt rather than iodine-enriched salt. Iodine deficiency appears to be most prevalent among women who eat plant-based vegan diets, but it is also seen among women with normal diets that include meat. This was demonstrated in a study from the University of South Australia. The challenge for pregnant women is to get adequate amounts of iodine and to find iodine-enriched table salt that has proper quality and does not contain anti-caking agents such as aluminum.
Iodine is very important for your metabolism and for ensuring a healthy pregnancy. The fetus grows rapidly over the nine-month period. It is therefore not difficult to imagine how active the metabolism is, also in terms of brain development. If a pregnant woman is severely iodine-deficient, she risks giving birth to a baby with dwarfism with mental retardation and physical disability. This condition is known as crenitism and affects one in 4,000 babies globally. It turns out that minor iodine deficiency can also have a negative impact on the pregnancy and the mental development of the baby.
Iodine deficiencies are common among vegetarians and meat eaters
The new pilot study was conducted by scientists from the University of South Australia. They compared iodine levels in urine from 31 vegans and 26 people with a mixed vegetable and animal diet. The urine samples revealed that iodine levels among the vegans were 44 mcg/L on average, while levels among meat eaters were 64 mcg/L. Nonetheless, none of the participants had levels that reached 100 mcg/L, which is what WHO considers to be sufficient.
Participants from both test groups who consumed pink Himalayan salt rather than iodine-enriched table salt were most iodine-deficient and had average iodine levels of 23 mcg/L. The new study is published in the International Journal of Environmental Research and Public Health.
Iodine deficiencies are a global problem
The new Australian study follows up on an American study showing that nearly two billion people worldwide lack iodine. As a result of this deficiency, around 50 million people have clinical diseases with thyroid disorders being the most common.
As mentioned earlier, iodine is highly important for the mental development of the fetus. According to Jane Whitbread, who is a dietician and one of the scientists behind the new Australian study, minor to moderate iodine deficiency can affect the child’s language skills, memory, and other cognitive skills.
Pregnant women are in particular need of iodine
The body’s need for iodine increases during pregnancy. Jane Whitbread advises pregnant women to take 150 micrograms of iodine per day as a supplement. Unfortunately, very few women do that. Iodine is found in fish, fish sauce, shellfish, eggs, algae, seaweed, and iodine-enriched salt. The amount of iodine in sea salt and Himalayan salt is very limited and is not sufficient to cover the daily need.
Iodine content in micrograms per 100 grams
Iodine enrichment of salt and foods is not enough
A major problem is that the agricultural soil in many parts of the world lacks iodine and that can affect the entire food chain. In Australia, where the link between low iodine intake and inadequate development of the mental capacity in babies is well known, the government decided to introduce the use of iodine-enriched salt in bread. Ever since, reports have shown that women who eat around 100 grams of non-organic, iodine-enriched break daily (the equivalent of three slices) have a five times greater chance of getting enough iodine compared with women who eat less bread. The average daily consumption of bread among women was around one slice.
In year 2000, mandatory iodine-enrichment of table salt was introduced in Denmark and has been upheld ever since because the population’s iodine intake was below the international recommendations. Bakers are also instructed to use iodine-enriched salt in their bread. Although the iodine intake in Denmark has increased, it is still too low – especially among pregnant women.
Remember that Himalayan salt and plant milk contain too little iodine
According to the Australian scientists, it is a problem that many people prefer sea salt or Himalayan salt. While these types of salt do contain more healthy minerals, they contain less iodine than enriched table salt. People who insist on using sea salt or Himalayan salt in their cooking must make sure to get iodine from other sources, as well.
One should avoid iodine-enriched table salt with aluminum and similar anti-caking agents. In animal studies, aluminum compounds have been shown to have a negative effect on the nervous system and fertility. If you want to use fine table salt, choose mineral salt that also contains sodium chloride and magnesium sulfate plus iodine.
Plant-based “milk products” also contain far less iodine than normal dairy products, the scientists say. Besides arguing for iodine enrichment of sea salt and Himalayan salt plus plant-based milk products, the scientists call for increased focus on the importance of getting enough iodine from the diet or from supplements. This goes for pregnant women as well as the general population.
University of South Australia. Poor iodine levels in women pose risks to fetal intellectual development in pregnancy. Science Daily
Jane S. et al. Iodine Excretion and Intake in Women of Reproductive Age in South Australia Eating Plant-Based and Omnivores Diets. International Journal of Environmental Research and Public Health 2021
Kristian Sjøgren. Derfor skal der være jod i dit husholdningssalt. Videnskab.dk 31. oktober 2018
Rychlik W. The need for iodine supplementation. OMS 12.06. 2017
Frederick R. Stoddard et al. Iodine Alters Gene expression in the MCF7 Breast Cancer Cell Line: Evidence for an Anti-Estrogen Effect of Iodine. International Journal of Medical Sciences. 2008
Frida - Parametre (fooddata.dk)