Posted by While browsing products in Japan, I came across an interesting dietary supplement marketed by the Noguchi Medical Research Institute. At first glance, it appeared to be a typical lemon-flavored cod liver oil and calcium supplement which further contains Vitamin A, Vitamin D, Vitamin C, folic acid, and lactic acid bacteria. However, a closer look at the ingredient list revealed something particularly interesting: beta-cyclodextrin – simply abbreviated as “cyclodextrin” was listed among the excipients.
What made this discovery even more interesting was the connection to Hideyo Noguchi, one of Japan’s most celebrated medical researchers. For decades, Noguchi’s portrait appeared on the Japanese 1000-yen banknote, making him one of the most recognizable scientific figures in the country. Many visitors to Japan will remember carrying the old 1000-yen bill featuring his image long before they learned about his remarkable scientific career.
Born in Fukushima Prefecture in 1876, Hideyo Noguchi overcame significant personal adversity to become an internationally respected bacteriologist. His research on infectious diseases and his relentless pursuit of scientific knowledge earned him a lasting place in Japanese history. Even today, his name remains synonymous with scientific curiosity, perseverance, and dedication.
It is therefore fitting to encounter a modern health product (technically a probiotic product) bearing the Noguchi name while simultaneously discovering a hidden piece of formulation science within it. The product serves as a reminder that innovation often occurs at multiple levels. Consumers may focus on vitamins, minerals, or fish oil, while formulation scientists appreciate the sophisticated excipients that help deliver these ingredients effectively.
Finding cyclodextrin listed on the label of a seemingly ordinary supplement was therefore a pleasant surprise. It highlighted how a technology originally developed through fundamental carbohydrate research has quietly become part of everyday products used by millions of people.
In a way, the experience connected two different aspects of scientific heritage. On one side was Hideyo Noguchi, on the other was cyclodextrin chemistry, a field that continues to transform modern formulation science through innovation that often remains hidden from view.
This is an interesting product marketed as Calcium PLUS Cod Liver Oil Gummies/Tablets (Lemon Flavor). Based on information available online, the ingredient list includes sugar, starch syrup (maltose), shark cartilage extract, powdered oblate, lactic acid bacteria powder, refined shark liver oil, shell calcium, cyclodextrin, magnesium carbonate, vitamin C, pectin, flavoring, glazing agent, emulsifier, vitamin A, folic acid, and vitamin D. Interestingly, despite the product name suggesting the presence of cod liver oil, the formulation appears to contain refined shark liver oil instead, and likely only in relatively small quantities. Another noteworthy component is cyclodextrin. Cyclodextrins are widely used to encapsulate oils and convert them into free-flowing powders, thereby improving stability, handling characteristics, and sensory properties. This may well be their primary function in this formulation. Researchers at Université Paris-Sud have published extensively on the use of cyclodextrins for oil encapsulation, and we have also successfully applied this technology to produce cod liver oil powders. However, when we previously discussed this approach with cod liver oil manufacturers in Iceland, the consensus was that the resulting product would be prohibitively expensive for the market. For this reason, it would be very interesting to learn more about this product, particularly the concentration and role of cyclodextrin in the formulation, as well as the encapsulation technology and manufacturing approach employed.
Thorsteinn Loftsson
Dear Professor Loftsson, thank you for your kind feedback. I checked the product website (https://noguchi-co.com/products/kan/dca/), and GPTed whether it contains cod or shark liver oil not being native Japanese, here is the explanation which is purely semantic and this is essentially another cultural surprise:
The “mistake” is mostly a historical naming issue.
In simple words:
Many Japanese people grew up eating sweets called “kanyū drops” (肝油ドロップ).
The word 肝油 (kanyū) literally means “liver oil”, and historically it referred to cod liver oil, which was given to children as a source of vitamins A and D.
Over time, manufacturers stopped using actual cod liver oil because vitamins A and D could be produced more easily and cheaply from other sources.
However, the old name remained because consumers recognized it and associated it with childhood nutrition.
Noguchi itself explains that modern “kanyū drops” often do not contain liver oil at all, and that the name has simply survived as a traditional product name. In this particular product, they chose to add a small amount of refined shark liver oil instead.
So the situation is:
What the name suggests: “These are cod liver oil drops.”
What the product actually contains: vitamins plus a small amount of shark liver oil.
What many Japanese consumers understand: “Kanyū drops” is just the traditional name of this type of vitamin candy, not a guarantee that it contains cod.
From a Western perspective, this can seem misleading, because a product called “cod liver oil drops” would normally be expected to contain cod liver oil. In Japan, however, the term has evolved into a generic, nostalgic name for a category of vitamin supplements.
Thank you István. Very interesting.