Scientists created a simpler, cheaper way to test if fish are getting enough vitamin B1 (thiamine), an important nutrient for reproduction and survival. The test measures an enzyme in fish livers that only works properly when vitamin B1 is available. This breakthrough could help fish farmers and researchers quickly identify vitamin B1 deficiencies in lake trout, salmon, and other fish species before it causes problems like reproductive failure or population decline. The new method is faster and more affordable than previous tests, making it easier to monitor fish health across different populations.

The Quick Take

  • What they studied: Whether a new, simpler test could accurately measure vitamin B1 availability in fish by checking an enzyme in their livers
  • Who participated: Two different strains of lake trout used to develop and test the new method
  • Key finding: The simplified test successfully measured vitamin B1 levels and could distinguish between vitamin B1 shortages and magnesium shortages, which both affect the same enzyme
  • What it means for you: If you work with fish farming or conservation, this test could help you quickly and cheaply identify vitamin B1 problems before they cause serious damage to fish populations. However, this is a laboratory tool, not a treatment, and more testing in different fish species is still needed

The Research Details

Researchers developed a new laboratory test to measure transketolase, an enzyme found in fish livers that requires vitamin B1 to function properly. The enzyme is like a worker that needs vitamin B1 as a tool—if the tool is missing, the worker can’t do the job. By measuring how well this enzyme works, scientists can figure out if a fish has enough vitamin B1.

The new test is simpler than older methods because it removes one expensive ingredient (called X5P) that was previously required. Instead, the test lets the fish’s own enzymes naturally create what’s needed. The researchers tested their method on two types of lake trout to make sure it worked accurately.

The test also includes a special feature: by running it with and without magnesium (another important mineral), scientists can tell whether a fish’s problem is caused by low vitamin B1 or low magnesium, since both affect the same enzyme.

This research matters because vitamin B1 deficiency is a real problem causing fish populations to decline in lakes. The old tests were expensive and complicated, so fish farmers and researchers couldn’t easily check many fish. A simpler, cheaper test means more frequent monitoring, earlier detection of problems, and better chances to fix the issue before it damages entire fish populations.

This is a methods development study, meaning the scientists created and tested a new tool rather than studying a large group of subjects. The study was published in a peer-reviewed scientific journal, which means other experts reviewed the work. The main limitation is that testing was done on only two lake trout strains, so the method still needs to be tested on other fish species to confirm it works universally. The researchers were transparent about what the test can and cannot do.

What the Results Show

The new simplified test successfully measured transketolase activity in lake trout livers and accurately reflected vitamin B1 (thiamine) availability. When researchers compared the enzyme activity to actual vitamin B1 levels in the fish, they matched up well, suggesting the test is reliable.

The test also worked when researchers varied the amount of vitamin B1 available, showing that it could detect both high and low vitamin B1 situations. Additionally, the method successfully identified when magnesium was limiting enzyme function versus when vitamin B1 was the problem—an important distinction because both nutrients affect the same enzyme.

By removing the expensive ingredient from previous tests, the researchers cut costs significantly while maintaining accuracy. The simplified procedure is also faster to perform, making it practical for testing many fish samples.

The test revealed that enzyme abundance (how much of the enzyme is present) and enzyme stability (how long it lasts) both affect the maximum activity levels observed. This means the test can provide information not just about vitamin B1 availability, but also about overall enzyme health in the fish. The framework also allows researchers to calculate specific values (EC50 and Vmax) that describe exactly how the enzyme responds to different vitamin B1 concentrations.

Previous methods for testing vitamin B1 in fish required expensive chemicals and more complex procedures, making them impractical for routine monitoring. This new approach builds on the same scientific principle (measuring transketolase activity) but simplifies it significantly. While the basic concept isn’t entirely new, the practical improvements make it much more useful for real-world fish farming and conservation work.

The study tested the method on only two lake trout strains, so it’s not yet clear if it works equally well for other fish species like Atlantic salmon or other predatory fish. The research is a methods development study rather than a large population study, so it doesn’t show how widespread vitamin B1 problems are in wild fish. The test measures enzyme activity in the lab, which may not perfectly reflect what’s happening in living fish. More research is needed to confirm the method works across different fish species and environmental conditions.

The Bottom Line

Fish farmers and conservation programs should consider adopting this new test for routine monitoring of vitamin B1 status in their fish populations (moderate confidence). The test appears most useful as a screening tool to identify which fish or populations need attention. However, this is a diagnostic tool, not a treatment—identifying a problem is only the first step. Once a deficiency is found, fish diets or environmental conditions would need to be adjusted. More research is needed before making species-specific recommendations.

Fish farmers raising lake trout, Atlantic salmon, or other predatory fish species should care about this research. Conservation biologists working to protect wild fish populations would benefit from this tool. Aquaculture facilities concerned about reproductive success and population health are the primary audience. General consumers don’t need to take action based on this research, as it’s a laboratory tool for professionals.

This is a tool development study, not a treatment study, so there’s no timeline for personal health benefits. For fish farmers, implementing this test could help identify problems within weeks of starting monitoring. However, fixing vitamin B1 deficiencies in fish populations would take longer—likely weeks to months depending on how the problem is addressed (dietary changes, environmental improvements, etc.).

Want to Apply This Research?

  • If you manage fish populations, track vitamin B1 test results monthly using the new transketolase assay, recording the enzyme activity levels and comparing them to baseline values to detect trends early
  • For fish farmers: implement quarterly vitamin B1 screening using this simplified test; adjust fish feed formulations or environmental conditions based on results to maintain optimal vitamin B1 levels
  • Establish a baseline vitamin B1 status for your fish population using this test, then monitor quarterly or after any dietary or environmental changes; track results over time to identify seasonal patterns or emerging deficiencies before they impact reproduction or survival

This research describes a laboratory testing method for measuring vitamin B1 availability in fish. It is intended for use by fish farming professionals, aquaculture facilities, and conservation researchers—not for self-diagnosis or treatment in humans. If you work with fish populations and suspect vitamin B1 deficiency, consult with a fish health specialist or veterinarian before making dietary or environmental changes. This study was conducted on lake trout strains and has not yet been validated across all fish species. Always follow your facility’s established protocols and consult with relevant regulatory agencies before implementing new testing or management practices.