Malabsorption

Even if someone’s diet seems to include plenty of a particular nutrient, if they aren’t absorbing the nutrients they are consuming they could still have deficiencies.  In the Discussion section of their paper, the authors of the LIFEHOUSE study (Stone et al., 2023) mention vertical ridging of the nails as an example of a symptom that could indicate protein or fat malabsorption.  They go on to mention other symptoms commonly seen with protein or fat malnutrition, pointing out that when there are several possible explanations for a given symptom, triangulating the most likely nutrients to target for an intervention can be done by looking at the constellation of symptoms and identifying trends.  A review they cite (Gommers et al., 2022) describes how proton pump inhibitors can cause malabsorption of magnesium, and that diuretic use can increase the risk.  They explain that magnesium is less soluble in a higher pH, and they cite several studies that would be worth looking into further suggesting that stopping proton pump inhibitors restores magnesium absorption but that simply supplementing with magnesium might not work.  They mention dietary fiber, probiotics and prebiotics as the most promising possibilities for acidifying the intestines by modifying the microbiome.  I would screen clients by asking what prescription or over the counter drugs or herbs they are taking and follow up with a serum magnesium test whenever there are symptoms of deficiency, given how common proton pump inhibitor use is and how essential magnesium is for the body. 

References:

Gommers, L. M. M., Hoenderop, J. G. J., & de Baaij, J. H. F. (2022). Mechanisms of proton pump inhibitor‐induced hypomagnesemia. Acta Physiologica, 235(4), 1–12. 

Stone, M., Lukaczer, D., D, A. C. R., Dotson, N., Volkov, A., Minich, D., Metti, D., Leary, M., Class, M., Carullo, M., Lundquist, E., Eck, B., Ordovas, J., Lamb, J., & Bland, J. (2023). LIFEHOUSE’s Functional Nutrition Examination (Physical Exam, Anthropometrics, and Selected Biomarkers) Informs Personalized Wellness Interventions. Journal of Personalized Medicine, 13(4).