Magnesium status in healthy free-living elderly Norwegians

Area of Science:

• Gerontology
• Nutritional Science
• Biochemistry

Background:

• Magnesium (Mg) status assessment in healthy elderly individuals is often inadequate.
• Subclinical Mg deficits may exist in this population, bypassing standard detection methods.

Purpose of the Study:

• To evaluate the Mg status in healthy elderly subjects.
• To compare Mg status between elderly and younger individuals.
• To investigate the effects of Mg supplementation on Mg status and renal function in the elderly.

Main Methods:

• Assessed Mg status using serum Mg, basal urinary Mg output, and a Mg loading test in 36 elderly and 53 younger subjects.
• Quantified dietary intake via a food frequency questionnaire.
• Administered oral Mg supplementation (300 mmol) to 14 elderly subjects to assess its impact.

Main Results:

• Elderly subjects showed higher Mg retention (28%) compared to younger controls (6%), suggesting Mg deficiency.
• Despite adequate nutrient intake (except vitamin D in women), serum Mg levels were within normal ranges, masking deficiency.
• Mg supplementation led to increased urinary Mg excretion, improved creatinine clearance, and reduced serum creatinine.

Conclusions:

• A significant subclinical magnesium deficit, undetectable by serum Mg levels, is prevalent in healthy elderly individuals.
• Magnesium supplementation effectively enhances Mg status and improves renal function in this demographic.