Salt - Is it Safe to Take This Much?

There is limited research that has looked at the long-term safety of increased salt intake in people who have orthostatic intolerance (OI). The biggest known risk would be for high blood pressure.

Increased blood pressure

Increased blood pressure is something to be checked and watched for people who have orthostatic intolerance conditions. For some people with orthostatic hypotension, they can have high blood pressure when they lie down. It happens at night more often(when the person is lying down, sleeping). Then, it is called "supine nocturnal hypertension". Go to the Secondary Conditions to learn more about Supine Nocturnal Hypertension.

Caution: If you have any of these conditions, you should work closely with your doctor before you start to increase fluids or salt: severe supine hypertension (high blood pressure when you lie down), uncontrolled high blood pressure or other medical conditions that have edema (swelling in your legs, feet or abdomen), like congestive heart failure or liver failure.1

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Iodine - Effect of High Amounts16

Taken from the NIH Fact Sheet for Professionals:
It is difficult to get too much iodine just from food. Most people only take in 200-300 mcg per day.

High intakes of iodine can cause some of the same symptoms as iodine deficiency—including goiter, elevated TSH levels, and hypothyroidism—because excess iodine in susceptible individuals prevents the creation of thyroid. THis y increases TSH stimulation, which can produce goiter. Iodine can also create hyperthyroidism usually when iodine is administered to treat iodine deficiency. Cases of acute iodine poisoning are rare and are usually caused by doses of many grams.

Acute poisoning symptoms include burning of the mouth, throat, and stomach; fever; abdominal pain; nausea; vomiting; diarrhea; weak pulse; and coma.

Responses to excess iodine and the doses required to cause adverse effects vary . Some people, such as those with autoimmune thyroid disease (like Grave's disease or Hashimoto's disease) and those who have been low on iodine at some point in their life, may be more sensitive to the effects of iodine than the general population. They may need to monitor their intake more closely. adverse effects with iodine intakes considered safe for the general population].

Tolerable Upper Intake Levels (ULs) for Iodine (Institute of Medicine)17

Age Male Female Pregnancy Lactation
Birth to 6 months Not possible to establish* Not possible to establish*    
7–12 months Not possible to establish* Not possible to establish*    
1–3 years 200 mcg 200 mcg    
4–8 years 300 mcg 300 mcg    
9–13 years 600 mcg 600 mcg    
14–18 years 900 mcg 900 mcg 900 mcg 900 mcg
19+ years 1,100 mcg 1,100 mcg 1,100 mcg 1,100 mcg

* Formula and food should be the only sources of iodine for infants.

Iodine in Table Salt

Iodine-containing compounds are added to table salt. Iodized salt is thus table salt mixed with a very, very small amount of potassium iodide, sodium iodide, or sodium iodate.


Iodine - Effect of Low Amounts

Iodized salt is used to help decrease the number of people who did not have enough iodine. Low iodine levels (iodine deficiency) affects about two billion people in the world. It is the leading preventable cause of mental retardation. Iodine was added to salt starting in 1924. Iodine deficiency commonly leads to thyroid gland problems - a 'goiter' which is a swelling of the thyroid gland, usually resulting in a bulbous protrusion on the neck. In the US, this was most common in parts of the country with low iodine in the soil and low intake of food from the ocean. Iodized table salt has significantly reduced disorders of iodine deficiency in countries where it is used.[35]  Not enough iodine results in low levels of thyroid hormones (hypothyroidism), goiter. Low amounts are more common in women and more common during pregnancy.


Iodine - Recommended Amount

Iodine is a 'trace mineral' - whcih means it is only needed in smal amounts but it is essential. It is needed for the cells to function nomrally and conver food into energy. The amount of iodine and the specific iodine compound added to salt varies from country to country. In the United States, the recommendation is for 150 micrograms of iodine per day for both men and women.

Table 1: Recommended Dietary Allowances (RDAs) for Iodine [2]

Age Male Female Pregnancy Lactation
Birth to 6 months 110 mcg* 110 mcg*    
7–12 months 130 mcg* 130 mcg*    
1–3 years 90 mcg 90 mcg    
4–8 years 90 mcg 90 mcg    
9–13 years 120 mcg 120 mcg    
14–18 years 150 mcg 150 mcg 220 mcg 290 mcg
19+ years 150 mcg 150 mcg 220 mcg 290 mc

A 1/4 teaspoon of iodized table salt provides 95 micrograms of iodine. (One teaspoon would provide 360 micrograms.) A 6-ounce portion of ocean fish provides 650 micrograms of iodine.

US iodized salt contains 46–77 ppm (parts per million), whereas in the UK the iodine content of iodized salt is recommended to be 10–22 ppm. 

Today, iodized salt is more common in the United States, Australia and New Zealand than in the United Kingdom.

If you are concerned about high levels of iodine, talk it over with your physician or a dietitian. You can also use some iodized salt and make up the rest with salt without iodine.





Why You Need to Raise the Head of Your Bed - and How Much


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  2. Freeman, Roy. Neurogenic orthostatic hypotension.NEJM 2008;358(6):615-624. Abstract
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  4. El-Sayed H, Hainsworth R. Salt supplementation increases plasma volume and orthostatic tolerance in patients with unexplained syncope. Heart 1996; 75:134–140.
  5. Thieben MJ, Sandroni P, Sletten DM, et al. Postural orthostatic tachycardia syndrome: The Mayo Clinic experience. Mayo Clin Proc. 2007;82:308–313
  6. Personal experience of author.
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  9. Rowe, Peter.General Information Brochure on Orthostatic Intolerance and Its Treatment. June 2010. Accessed from http://www.cfids.org/webinar/cfsinfo2010.pdf. Accessed May 28.2012.
  10. U.S. Department of Agriculture, Agricultural Research Service. 2011. USDA National Nutrient Database for Standard Reference, Release 24. Nutrient Data Laboratory Home Page ,http://www.ars.usda.gov/ba/bhnrc/ndl  External Link
  11. Low PA and Singer W. Update on Management of Neurogenic Orthostatic Hypotension. Lancet Neurol. 2008 May; 7(5): 451–458. Abstract. Article PDF.
  12. Low PA, Sandroni P, Joyner and Shen W. Postural Tachycardia Syndrome (POTS). J Cardopvasc Electrophysiology 2009; 20:352-358.  Abstract.  Article PDF
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  14. Fu Q, Vangundy TB, Galbreath MM, Shibata S, Jain M, Hastings JL, Bhella PS, Levine BD. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol. 2010 Jun 22;55(25):2858-68. Abstract. Article PDF
  15. "Iodine in diet". MedlinePlus. External Link.External link Last accessed 09.13.2012
  16. Dietary Supplement Fact Sheet: Iodine. Office of Dietary Supplements. National Institutes of Health. External Link. Last accessed 09.13.2012.
  17. Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academy Press: Washington DC, 2001. 2001. External Link External Link

Author: Kay E. Jewell, MD
Page Last Updated: September 13, 2012