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Explore dietary patterns, glucose, body composition, nutrients and metabolic markers through practical, evidence-linked guides.

41 published guidesBrowse the complete library

Illustrated nutrition and metabolic health guide with glucose context

Nutrition & Metabolic Health

Published guides

Nutrition & Metabolic Health

41 results

In-depth guideBlood tests and biomarkers.1,25-Dihydroxy Vitamin D (Calcitriol): Test & MeaningLearn what the 1,25-dihydroxy vitamin D blood test measures, when calcitriol testing is useful, and why 25-hydroxy vitamin D checks stores instead.Updated 24 Aug 202610 minute read

In-depth guideBlood tests and biomarkers.Transferrin Saturation: Formula, Low & High ResultsUnderstand the transferrin saturation formula, why ferritin and inflammation matter, common low and high patterns, sample variation, and sensible follow-up.Updated 28 Aug 202615 minute read

In-depth guideSupplementsSelenium Supplements: Benefits, Dose, Food Sources and SafetyA careful selenium guide covering essential functions, food variability, studied doses, cancer and thyroid evidence, US and European upper limits, interactions and toxicity signs.Updated 4 Sept 202616 minute read

In-depth guideSupplementsNiacin SupplementsCompare niacin forms, understand why better cholesterol numbers did not establish added cardiovascular benefit in statin trials, and review high-dose safety.Updated 9 Sept 20265 minute read

In-depth guideSupplementsZinc supplements: benefits, dosage, forms and copper safetyA practical zinc guide covering deficiency, colds, elemental dose, forms, copper depletion, interactions, blood tests and who should avoid high doses.Updated 8 Aug 202624 minute read

In-depth guideBlood tests and biomarkers.Anion Gap Blood Test: Formula, High & Low ResultsUnderstand the anion gap formula, why laboratory ranges differ, what high or low results can mean, and why electrolytes, albumin and symptoms matter.Updated 27 Aug 202613 minute read

In-depth guideBlood tests and biomarkers.Apolipoprotein A1 (ApoA1): Test & MeaningUnderstand ApoA1, how it differs from HDL cholesterol, why a low result needs context, and how ApoB and the full lipid profile complete interpretation.Updated 30 Aug 202615 minute read

In-depth guideBlood tests and biomarkers.C-Peptide Blood Test: Meaning, Units and ContextUnderstand what a C-peptide result says about your body's own insulin production, and why glucose, timing, kidney function, medicines and the assay matter.Updated 3 Sept 202616 minute read

In-depth guideBlood tests and biomarkers.Cystatin C Blood Test: eGFR, Results & LimitationsUnderstand cystatin C, combined creatinine-cystatin C eGFR, factors that can distort results, and how kidney function is assessed with trends and urine albumin.Updated 28 Aug 202615 minute read

In-depth guideBlood tests and biomarkers.Bicarbonate (Total CO₂): High & Low ResultsLearn why chemistry-panel total CO₂ mostly reflects bicarbonate and how anion gap, kidneys, breathing and sample handling explain high or low results.Updated 30 Aug 202616 minute read

In-depth guideBlood tests and biomarkers.ALT Blood Test: High, Low, Ranges & What It MeansUnderstand an ALT blood test, why ranges vary, what high or low ALT can mean, U/L and µkat/L conversion, confounders and safe next steps.Updated 15 Aug 202618 minute read

In-depth guideBlood tests and biomarkers.Calcium Blood Test: Total vs Ionized, High and LowUnderstand the calcium blood test, including total versus ionized calcium, albumin context, report intervals, related tests and symptom-led safety guidance.Updated 4 Sept 202613 minute read

In-depth guideBlood tests and biomarkers.Magnesium Blood Test: Low, High, Limits and MeaningLearn what a magnesium blood test measures, how to read low or high flags, why serum has limits, and which report context and symptoms matter.Updated 4 Sept 202613 minute read

In-depth guideSupplementsVitamin A: Benefits, Dose, Retinol, Beta-Carotene & Safety | LongevityMateEvidence-based vitamin A guide covering retinol vs beta-carotene, dose and IU conversion, pregnancy, smokers, toxicity, deficiency, food, forms and testing.Updated 10 Aug 202638 minute read

In-depth guideSupplementsVitamin E Supplements: Evidence, Label Units and SafetyUnderstand vitamin E supplement evidence, natural and synthetic label units, prevention-trial findings, bleeding risks and when clinical advice matters.Updated 8 Sept 20265 minute read

In-depth guideBlood tests and biomarkers.24-Hour Urine Protein: Test & ResultsUnderstand total protein in a 24-hour urine collection, how it differs from albumin and UACR, collection errors and what high results can mean.Updated 31 Aug 202614 minute read

In-depth guideSupplementsAlpha-Lipoic Acid: Neuropathy Evidence, Forms, Dose & SafetyEvidence-graded alpha-lipoic acid guide covering oral versus IV neuropathy evidence, studied doses, metabolic claims, R-ALA limits, interactions, side effects and high-risk groups.Updated 3 Sept 202616 minute read

In-depth guideSupplementsPsyllium: Benefits, Dose, Cholesterol & Safety | LongevityMateEvidence-based psyllium guide covering constipation, LDL and ApoB, blood sugar, dose, water, timing, interactions, forms, pregnancy and side effects.Updated 10 Aug 202632 minute read

In-depth guideSupplementsRiboflavin: Migraine Dose, Benefits, R5P & Safety | LongevityMateEvidence-based riboflavin guide covering vitamin B2 deficiency, the 400 mg migraine dose, R5P forms, absorption, pregnancy, tests, side effects and safety.Updated 10 Aug 202635 minute read

In-depth guideBlood tests and biomarkers.Uric Acid Blood Test: High Results, Gout and MeaningUnderstand a uric acid blood test, high and low results, gout treatment targets, kidney excretion, urine testing and questions for your clinician.Updated 4 Sept 202613 minute read

In-depth guideSupplementsBerberine: Benefits, Dose, Weight Loss & Safety | LongevityMateEvidence-based berberine guide covering glucose, cholesterol, weight loss, dose, forms, side effects, pregnancy, medicine interactions and product quality.Updated 11 Aug 202638 minute read

In-depth guideSupplementsLutein Supplements: Eye Evidence, Dose, Food Sources and SafetyA clear lutein guide covering AREDS2, intermediate AMD, lutein plus zeaxanthin, studied doses, food and label checks, smoking warnings, interactions and uncertainty.Updated 4 Sept 202616 minute read

In-depth guideBlood tests and biomarkers.Total Protein Blood Test: High, Low and A/G ContextLearn what a total protein blood test measures, how albumin and globulin shape A/G context, and how to read high or low results safely.Updated 4 Sept 202613 minute read

In-depth guideBlood tests and biomarkers.UACR Test: Urine Albumin-Creatinine Ratio ExplainedUnderstand what a UACR urine test measures, the A1 to A3 categories, why repeat testing matters, and how UACR works with eGFR to assess kidney health.Updated 27 Aug 202614 minute read

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