Which Micronutrients Are Worth Testing

Testing beats guessing, and the list of genuinely useful tests is shorter and cheaper than a year of supplements.

The core list

Vitamin B12, particularly for anyone over fifty, on long-term metformin or acid-suppressing medication, or avoiding animal foods. Ferritin with a full blood count, and CRP alongside to interpret it. Vitamin D, particularly at higher latitudes. Thyroid function. Fasting glucose or HbA1c. Folate. These are inexpensive, widely available and cover the most common correctable causes of cognitive complaints.

What is less useful

Broad panels of trace minerals with no clinical indication, which mostly generate uninterpretable results. Hair mineral analysis, which lacks validation for nutritional assessment. Most direct-to-consumer micronutrient panels, which test many things with poorly defined reference ranges and no clinical context. Serum magnesium, which is a poor indicator of body stores despite being commonly ordered.

Interpreting results

Reference ranges describe a population, so healthy people fall outside them and being inside one does not guarantee optimal status. Borderline B12 may warrant methylmalonic acid testing. Ferritin rises with inflammation. And a critical practical point: high-dose biotin, common in hair and nail supplements, interferes with many immunoassays including thyroid tests and can produce clinically misleading results. Tell whoever orders your tests what supplements you take.

Where a supplement fits here

If you have worked through the medical and behavioural options above and want to add a supplement, Cognicept is a liquid formula available from the Cognicept official website. We would rather you addressed sleep, activity, hearing and any underlying medical cause first — those have far stronger evidence than anything in a bottle, including ours. See our honest assessment for the full picture.