In this chapter, electrolytes will be explained before learning more about the four electrolyte micronutrients. Then, hypertension will be discussed, along with the impact of these micronutrients on the condition.
- 13.1: Electrolytes
- Electrolytes are compounds that separate into ions (molecules with a charge) in water. Electrolytes can be separated into two classes: Cations: ions that have a positive charge Anions: ions that have a negative charge.
- 13.2: Sodium Ions
- Salt (NaCl) contributes almost all the sodium that we consume. 75-85% of the salt we consume is from processed foods, 10% is naturally in foods, and added salt contributes 10-15% of total salt intake. 95-100% of consumed sodium is absorbed. Sodium is taken up into the enterocyte through multiple mechanisms before being pumped out of the enterocyte by sodium-potassium (Na+/K+) ATPase
- 13.3: Chloride Ions
- Sodium's partner in salt, chloride, is the major extracellular anion. Almost all of the chloride we consume is from salt, and almost all chloride is absorbed. It is excreted in urine like sodium.
- 13.4: Potassium Ions
- Potassium is the major intracellular cation. Good sources of potassium include beans, potatoes (with skin), milk products, orange juice, tomato juice, and bananas. Potassium, like sodium and chloride, is well absorbed. Greater than 85% of consumed potassium is absorbed. Potassium is primarily excreted in urine (~90%).
- 13.5: Magnesium Ions
- Magnesium is an electrolyte, but that is not considered its major function in the body. Green leafy vegetables, beans, nuts, seeds, and whole grains are good sources of magnesium. 40-60% of consumed magnesium is absorbed at normal levels of intake. Magnesium is excreted primarily in urine. 55-60% of magnesium in the body is found in bone. Some (30%) of this bone magnesium is believed to be exchangeable, or can be used to maintain blood concentrations.
- 13.6: Hypertension, Salt-Sensitivity & the DASH Diet
- Approximately 27% of American adults have hypertension (high blood pressure), which increases their risk of developing cardiovascular disease1. Salt and/or sodium intake is believed to be a major causative factor in the development of hypertension. However, it is now known that not everyone is salt-sensitive. Salt-sensitive means that a person’s blood pressure increases with increased salt intake and decreases with decreased salt intake.
Thumbnail: A pile of iodized salt. Image used with permission (CC BY-SA 3.0; Drtony999).