Algae, particularly certain species like spirulina and chlorella, have been included in some dietary supplements marketed for supporting nail health. The scientific rationale behind this is primarily due to the nutrient-rich profile of these algae. They are sources of proteins, vitamins (such as biotin and vitamin E), minerals (including iron and magnesium), and antioxidants, all of which are important for the maintenance of healthy nails. Deficiencies in some of these nutrients, notably biotin, have been associated with brittle nails.

However, direct scientific research specifically linking algae consumption to improved nail health in humans is very limited. Most of the supporting evidence is extrapolated from the known nutritional content of algae and general knowledge about the nutrients involved in nail structure and growth. A few small clinical studies have shown that supplementation with spirulina may improve hair and nail quality, but these studies are limited in size and scope and often include other nutrients or lack a strong control group. There is currently insufficient clinical evidence to conclusively say that algae supplementation directly benefits nail health beyond what could be achieved through adequate overall nutrition.

In conclusion, while there is a scientific rationale based on nutrient content, direct evidence for the effectiveness of algae in supporting nail health is weak, and more robust clinical studies are needed.