Lithothamnium calcareum is a red seaweed that has its habitat in the Atlantic Ocean near the coast of Ireland. It contains calcium, magnesium (in the form of carbonates), iron, zinc, manganese, alginates, ascorbic acid.

Calcium-Rich Composition

Lithothamnium calcareum is known for its high calcium content. It absorbs calcium and other trace minerals from seawater, which are then deposited in its cell walls, forming a hard, calcareous skeleton.

Marine Habitat

This algae typically grows in marine environments, often found in deeper, cooler waters. It prefers areas with strong currents and clean water, which provide a steady supply of nutrients.

Environmental Indicator

Due to its sensitivity to changes in water quality and temperature, Lithothamnium calcareum is often used as an environmental indicator. Changes in its growth and distribution can signal shifts in marine conditions.

Uses in Supplements

It is commonly used in dietary supplements, particularly for its calcium content. These supplements are often marketed for bone health, given the high bioavailability of the calcium in Lithothamnium calcareum.

Other Minerals

Besides calcium, it also contains other essential trace minerals like magnesium, sodium, and potassium, making it a multi-mineral resource.

Alkalizing Properties

Some proponents claim that Lithothamnium calcareum has alkalizing effects on the body, which can help balance pH levels. However, scientific evidence to fully support these claims is limited.

Sustainability Concerns

While it is a natural resource, there are concerns about the sustainability of harvesting Lithothamnium calcareum, particularly in areas where it is collected in large quantities.

Research and Studies 

There is ongoing research into the potential health benefits and applications of Lithothamnium calcareum. While some studies suggest benefits for bone health and acid-base balance in the body, more comprehensive research is needed to fully understand its effects and efficacy.

However, it also contains non-essential or toxic elements such as aluminium and titanium (1).

It is used in the medical sector as a combination of chemotherapy (2).

References_______________________________________________________________________ 

(1) Desideri D, Cantaluppi C, Ceccotto F, Meli MA, Roselli C, Feduzi L. Essential and toxic elements in seaweeds for human consumption.    J Toxicol Environ Health A. 2016;79(3):112-22. doi: 10.1080/15287394.2015.1113598.

Abstract. Essential elements (K, Ca, P, S, Cl, Mn, Fe, Cu, Zn, Ni, Br, and I) and nonessential or toxic elements (Al, Ti, Si, Rb, Sr, As, Cd, Sn, and Pb) were determined by energy-dispersive polarized x-ray fluorescence spectrometry in 14 seaweeds purchased in local specialty stores in Italy and consumed by humans. The differences in elements between the algae species reached up to 2-4 orders of magnitude. Lithothamnium calcareum showed the highest levels of Ca, Al, Si, Fe, and Ti. Palmaria palmata showed the highest concentrations of K, Rb, and Cl. The highest content of S was in Chondrus crispus. Laminaria digitata contained the highest concentrations of total As, Cd, Sn, Br, and I. The highest concentration of Zn was in Chlorella pyrenoidosa. Ulva lactuca displayed the highest levels of Cu, Ni, Mn, and Pb. Iodine levels ranged from 3.4 in Chlorella pyrenoidosa to 7316 mg/kg(dry) in Laminaria digitata. The nutrimental importance of essential elements was assessed using nutritional requirements. The results showed that the consumption of algae might serve as an important source of the essential elements. Health risk due to the toxic elements present in seaweed was estimated using risk estimators. Total As, Cd, and Pb concentrations ranged from <1 to 67.6, to 7.2 and to 6.7 mg/kg(dry) respectively; therefore, their contribution to total elemental intake does not appear to pose any threat to the consumers, but the concentrations of these elements should be controlled to protect the consumer against potential adverse health risks.

(2)  Imperatori L, Giardini D, Latini G, Migliori G, Blasi C, Bunkheila F, Breschi C, Mattioli R, Pelliccioni S, Laurino C, Vadalà M, Palmieri B, Iannitti T.  Feasibility single-arm study of a medical device containing Desmodium adscendens and Lithothamnium calcareum combined with chemotherapy in head and neck cancer patients.  Cancer Manag Res. 2018 Nov 8;10:5433-5438. doi: 10.2147/CMAR.S165746

Abstract. Background: Neoplasms of the head and neck represent approximately 5% of cancers and they require complex multidisciplinary clinical management. Desmodium adscendens (Desmodium) is a plant that possesses anti-allergic, antioxidant and hepatoprotective properties. Lithothamnium calcareum (Lithothamnium) is a calcified seaweed that possesses remineralization properties and the ability to maintain homeostasis. Aim: In this single-arm study, we investigated the efficacy of a combination therapy based on Desmovit® which contains Desmodium and Lithothamnium, and chemotherapy in patients with head and neck cancer....Conclusion: We found that chemotherapy, combined with Desmodium and Lithothamnium, improved pain and fatigue in head and neck cancer patients, although we cannot confirm if this was due to Desmodium and Lithothamnium or chemotherapy. The improvement in pain and fatigue was supported by the ECOG performance status remaining stable with the highest score being equal to 2 throughout the study and a trend towards an improvement in GPS performance status and albumin levels.