CORAL REEFS AND METABOLIC ACIDOSIS

Coral reefs are ecosystems. Coral is an animal that attaches itself to the ocean floor and secretes a hard calcium carbonate exoskeleton, and its existence dates back to the Ordovician Period, 485 million years ago. In 2008, studies demonstrated that while acidity (pH) and carbon dioxide dissolved in water, (dissolved CO2 is referred to as pCO2) do not compromise the coral animal’s ability to perform photosynthesis, they do decrease its ability to create its calcified exoskeleton (1). As the amount of carbon dioxide in our atmosphere increases, a relatively small amount of it dissolves in water. This dissolved pC02 in the water will form carbonic acid (H2CO3) and cause calcium rocks or coral to dissolve. As the seas become more acidic, the coral reef habitats are eroding. In fact, in 2020 Renee Setter of the University of Hawaii Manoa presented data at the Ocean Sciences Meeting showing some reefs will disappear within the next 25 years. The coral reefs are home to 25% of all marine species, and their decline will severely affect the fishing industry. 

Like coral, bone comprises calcium and surrounds cells that secrete a hard matrix. As kidney disease progresses, the kidney excretes less and less acid, and acid molecules (H+) accumulate. These acids need to be buffered, and in order to do this, a portion of calcium must move from bone into the blood, weakening bones. In kidney disease the serum phosphorus and inflammation work in concert with the excess calcium to form calcium deposits in blood vessels, making them stiffer, potentiating heart failure, and worsening hypertension.

This all happens early in kidney disease, but by increasing the base content, through bicarbonate supplements, or through consuming more fruits and vegetables in the diet, we can provide suitable buffers, so that the acids do not have to bother the bones. Helping correct metabolic acidosis will not only keep the bones stronger, help reduce the consequences of heart disease and hypertension, but will help keep the muscles from deteriorating. It has also been demonstrated to slow the progression of chronic kidney disease (2).

1. Marubini F, Ferrier-Pagès C, Furla P, Allemand D. Coral calcification responds to seawater acidification: a working hypothesis towards a physiological mechanism. Coral Reefs. 2008;27(3):491-9.

2. Madias NE. Metabolic Acidosis and CKD Progression. Clin J Am Soc Nephrol. 2021;16(2):310-2.