Optimal - The Blog

January 30, 2023

Water, Water, Everywhere…Nor Any Drop To Drink

But we must find and drink plenty of pure, clean water to support our metabolism and health and to replenish what is lost on a daily basis.

You can use Functional Blood Chemistry Analysis to identify dehydration, and take steps to address it and prevent it down the road.

Several blood chemistry biomarkers help to evaluate dehydration, including BUN, sodium, potassium, chloride, RBCs, hemoglobin, and hematocrit. These should be assessed in conjunction with an individual’s history and clinical presentation.

Assessing dehydration should incorporate serum biomarkers, clinical signs and symptoms, individual history, fluid intake, and fluid losses. Many individuals do not consume enough water or fluids and fail to meet general daily fluid recommendations for adults of 2.7-3.7 liters (approximately 11.25 – 15.4 cups), though some of that fluid can be obtained from foods such as fruits and vegetables. Many don’t realize how much fluid can be lost from activities and heat exposure, an amount that can exceed 6 liters per day (25 cups/day) (Popkin 2010).

The following biomarkers and clinical conditions should be taken into account (Ekman 2020, Lacey 2019, Pagana 2021, Popkin 2010, Raymond 2021), Smith 2013, Taylor 2022, Zhang 2019):

Biomarkers of dehydration  

  • Elevated
    • Serum sodium, potassium, chloride, BUN, creatinine, albumin, RBC count, hemoglobin, hematocrit
    • Bun/creatinine ratio above 18
    • Plasma hyperosmolality, i.e., elevated serum osmolality of above the normal 285-295 mOsm/kg H2O (285-295 mmol/kg)
    • Concentrated urine, increased urine osmolality (3-4 times plasma osmolality), elevated specific gravity, acidic urine
  • Decreased
    • Glomerular filtration rate

Clinical signs and causes of dehydration

  • Decreased total blood volume, hypovolemia
  • Low blood pressure, orthostasis
  • Reduced renal blood flow
  • Weakness, dizziness, fatigue
  • Poor skin turgor
  • Kidney stones
  • Acute weight loss of greater than 3% over 7 days
  • Total body water below 69%
  • Delirium, compromised cognitive function, including impaired memory and attention
  • Sudden cardiac death following acute coronary artery syndrome

Plasma Osmolality (pOsm)

Plasma osmolality (number of solute particles per kg of solvent) increases with dehydration and decreases with overhydration, though other causes can also alter it. For example, increased pOsm can occur with hypernatremia, hyperglycemia, hypercalcemia, renal dysfunction, and ketosis. Decreased pOsm can occur with hyponatremia and the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Normal plasma osmolality in adults is 285-295 mOsm/kg H20. Values above 385 are associated with stupor in those with hyperglycemia, 400-420 increases the risk of grand mal seizures, and values above 420 can be fatal. The pOsm can be calculated from blood biomarkers (Pagana 2021):

Plasma Osmolality (mOsm/kg) = 2 x sodium + glucose/18 + BUN/2.8

Causes of dehydration

  • Inadequate fluid intake
  • Excess fluid loss via the kidneys, sweating, vomiting, and diarrhea
  • Excessively hot weather
  • Diuretics, laxatives, polypharmacy

Healthy Beverages to Meet Your Fluid Needs

Drink plenty of good, clean water. Water purified via reverse osmosis or distillation removes the bad and the good, e.g., heavy metals, nucleotides, many microorganisms, and essential minerals, including magnesium, calcium, zinc, and lithium Conti 2005, Vema 2014, Quattrini 2016). Softening water also removes important minerals. Alternate sources of minerals and trace elements should be consumed to ensure adequate intake.

You can also make some healthy beverages, including organic coffee, tea, homemade lime, and lemonade. See the ODX blog about Green Lemonade.

And it’s essential to plan to hydrate… don’t wait until you’re thirsty because thirst can lag behind your hydration needs. Thirst may not kick in until you are already dehydrated, as indicated by a decreased body mass of 1-2% (Nolan 2020).

Try drinking 1-2 cups of water (8-16 ounces, 120-240 mL) first thing in the morning and then repeat between meals to help meet your total fluid needs. Other beverages, soups, fruits, and vegetables also help meet your needs. Another easy trick is to keep a favorite 1-liter (~4 cups) water bottle with you and be sure to fill it 2-3 times per day. Also, it is essential to know your needs and add on any replacement needs due to losses (sweating or gastrointestinal losses). Our bodies are approximately 60% water… so be sure to HYDRATE, and NOT DEHYDRATE!

Adequate fluid intake based on gender (Popkin 2010):

Females:         2700 mL/day (11.25 cups/day) or 1 mL/Kcal energy requirement    

Males:             3700 mL/day (15.4 cups/day) or 1.54 mL/Kcal energy requirement

An alternative way of determining fluid needs is based on weight (Raymond 2021):

35 mL per kg of usual body weight, e.g., if you weigh 80 kg (176 pounds), you need 2800 mL (11.7 cups) of fluid per day. Needs are individualized for increased BMI and obesity.

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Tag(s): Biomarkers

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