THE PURSER WELLNESS ENCYCLOPEDIA

Let’s explore “Vitamin B9 / folate deficiency”

Explore this topic as a step-by-step interactive map.MTHFR, the citric acid cycle & ATP
A RELATED COURSEGetting to know your micronutrients

5 chapters, at your pace

Explore the course
Explore all 2 matching courses

763 resources for your curiosity122 matching listings grouped; alternative sources stay available.

What’s searchable?
Nutrient referenceSep 23, 2026

Green Tea

Some search terms matched

…APA result. A cell-response finding is not a diagnosis of a deficiency in this botanical or compound. Brewed green tea and concentrated green-tea extracts differ in caffeine and catechin exposure. What symptoms can—and cannot—tell you Ther…

Nutrient referenceSep 23, 2026

Histidine

Some search terms matched

…e or a laboratory finding is not automatically a standalone deficiency diagnosis. Assess overall protein intake, absorption and the clinical setting with a qualified clinician. Food sources Protein foods such as eggs, fish, poultry, meat, d…

Nutrient referenceSep 23, 2026

Inositol

Some search terms matched

…o come up when reviewing blood sugar, chromium, zinc, and B vitamins. Which connection matters depends on your actual results and goals. Putting the pieces together This is a useful example of why Dr. Purser prioritizes a pattern instead of…

Nutrient referenceSep 23, 2026

Iodine

Some search terms matched

…e What it does Is needed to make thyroid hormones. Possible deficiency symptoms Low intake can contribute to an enlarged thyroid and impaired thyroid hormone production. Symptoms are not specific. How supplementation is approached Review io…

Nutrient referenceSep 23, 2026

Isoleucine

Some search terms matched

…e or a laboratory finding is not automatically a standalone deficiency diagnosis. Assess overall protein intake, absorption and the clinical setting with a qualified clinician. Food sources Protein foods such as eggs, fish, poultry, meat, d…

Nutrient referenceSep 23, 2026

Lavender

Some search terms matched

…APA result. A cell-response finding is not a diagnosis of a deficiency in this botanical or compound. Lavender may be used as an aroma or in a product specifically formulated for oral use. Do not ingest a fragrance or topical essential oil…

Nutrient referenceSep 23, 2026

Leucine

Some search terms matched

…e or a laboratory finding is not automatically a standalone deficiency diagnosis. Assess overall protein intake, absorption and the clinical setting with a qualified clinician. Food sources Protein foods such as eggs, fish, poultry, meat, d…

Nutrient referenceSep 23, 2026

Lipoic Acid

Some search terms matched

…oms can—and cannot—tell you There is no established dietary deficiency syndrome for this specific botanical or compound. Symptoms are not evidence that you need this supplement. Food sources Small amounts occur in foods such as organ meats …

Nutrient referenceSep 23, 2026

Lycopene

Some search terms matched

…APA result. A cell-response finding is not a diagnosis of a deficiency in this botanical or compound. Lycopene is a carotenoid found in foods such as tomatoes; a concentrated capsule is a separate supplement decision. What symptoms can—and…

Nutrient referenceSep 23, 2026

L-Lysine

Some search terms matched

…e or a laboratory finding is not automatically a standalone deficiency diagnosis. Assess overall protein intake, absorption and the clinical setting with a qualified clinician. Food sources Protein foods such as eggs, fish, poultry, meat, d…

Nutrient referenceSep 23, 2026

Magnesium

Some search terms matched

…tes in energy production. Also called: Magnesium, magnesium deficiency, muscle cramps A cofactor across several systems Dr. Purser’s course places magnesium in energy, muscle, nerve, sleep and insulin-related discussions. It teaches mineral…

Nutrient referenceSep 23, 2026

Maitake

Some search terms matched

…APA result. A cell-response finding is not a diagnosis of a deficiency in this botanical or compound. Maitake mushrooms eaten as food differ from concentrated mushroom extracts and immune-support blends. What symptoms can—and cannot—tell y…

Search looks for your words in titles, descriptions, available articles, learning guides, and video captions when available. The closest matches appear first. Duplicate posts are grouped, with links to other places you can read or watch them. Books, chapters, and reports have topic guides here; the original files and full book text are not available in this encyclopedia. Subscriber posts include a title and public summary; open Substack to read the full post.