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Connect nutrition with the health signals that matter

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 biomarkers1,25-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 Aug 24, 202610 minute read

In-depth guideBlood tests and biomarkersTransferrin 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 Aug 28, 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 Sep 4, 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 Sep 9, 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 Aug 8, 202624 minute read

In-depth guideBlood tests and biomarkersAnion 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 Aug 27, 202613 minute read

In-depth guideBlood tests and biomarkersApolipoprotein 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 Aug 30, 202615 minute read

In-depth guideBlood tests and biomarkersC-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 Sep 3, 202616 minute read

In-depth guideBlood tests and biomarkersCystatin 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 Aug 28, 202615 minute read

In-depth guideBlood tests and biomarkersBicarbonate (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 Aug 30, 202616 minute read

In-depth guideBlood tests and biomarkersALT 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 Aug 15, 202618 minute read

In-depth guideBlood tests and biomarkersCalcium 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 Sep 4, 202613 minute read

In-depth guideBlood tests and biomarkersMagnesium 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 Sep 4, 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 Aug 10, 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 Sep 8, 20265 minute read

In-depth guideBlood tests and biomarkers24-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 Aug 31, 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 Sep 3, 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 Aug 10, 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 Aug 10, 202635 minute read

In-depth guideBlood tests and biomarkersUric 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 Sep 4, 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 Aug 11, 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 Sep 4, 202616 minute read

In-depth guideBlood tests and biomarkersTotal 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 Sep 4, 202613 minute read

In-depth guideBlood tests and biomarkersUACR 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 Aug 27, 202614 minute read

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