Your Minerals Aren't Absorbing. Your Genes Know Why.

MTHFR encodes the enzyme that converts folate into the active form your cells actually use. This isn’t just about B vitamin metabolism; it’s about whether your mitochondria can generate energy. MTHFR also controls methylation, the chemical reaction that runs your entire detoxification system, your immune response, your neurotransmitter synthesis, and your ability to repair DNA.

The C677T variant, carried by roughly 40% of people with European ancestry, reduces MTHFR enzyme activity by 40 to 70 percent. That means your cells are trying to run methylation and energy production on a fraction of the enzymatic capacity they need. You can eat unlimited leafy greens and still be functionally B12 and folate deficient at the cellular level.

You notice this as relentless fatigue, brain fog, mood instability, delayed wound healing, and recurrent infections. Methylation powers every detoxification reaction; when it’s impaired, toxins accumulate. Your mitochondria run out of fuel. Your neurotransmitters don’t get made properly.

VDR encodes the vitamin D receptor, the protein that sits on the surface of nearly every cell in your body and determines whether circulating vitamin D actually does anything inside that cell. Vitamin D isn’t just about bone health; it controls your immune response, mitochondrial function, calcium regulation, and gene expression. A faulty or inefficient receptor means vitamin D can’t activate, no matter how high your blood levels are.

The BsmI, FokI, and TaqI variants are extremely common, carried by roughly 30 to 50 percent of the population depending on ancestry. People with certain VDR variants require 2 to 3 times higher circulating vitamin D levels to achieve the same intracellular effect as people without the variant. Your body either absorbs vitamin D poorly, or the receptor doesn’t respond efficiently to what you do absorb.

You experience this as weak bones, recurrent infections, poor wound healing, muscle weakness, and mood dysregulation. Your immune cells can’t differentiate properly. Your mitochondria underperform. Calcium regulation fails, leaving you susceptible to both osteoporosis and inappropriate calcification.

HFE encodes the protein that regulates hepcidin, the hormone that controls whether your intestines absorb iron or block it. Iron is essential for oxygen transport, energy production, immune function, and myelin formation in your brain. Too little iron and you collapse. Too much iron and you generate free radicals that accelerate aging and organ damage. HFE keeps this balance.

The H63D variant is carried by roughly 15 to 20 percent of people with European ancestry, and it creates mild to moderate iron dysregulation. Carriers often absorb iron less efficiently than people without the variant, leaving them susceptible to iron-deficiency anemia despite adequate dietary intake. Some carriers absorb iron too well and develop secondary iron overload.

You notice this as bone-deep fatigue, shortness of breath on exertion, dizziness, brain fog, and cold hands and feet. Your mitochondria can’t make ATP without iron. Your immune cells can’t generate reactive oxygen species to kill pathogens. Your myelin production slows, impairing nerve signal speed.

BCMO1 encodes the enzyme that converts plant-based beta-carotene (the orange pigment in carrots, sweet potatoes, and kale) into retinol, the active form of vitamin A your body actually uses. Vitamin A is essential for vision, immune function, gene expression, and reproduction. Unlike most vitamins, your body can’t make vitamin A from scratch; it has to come from food, either as preformed retinol from animal sources or as beta-carotene that gets converted.

The R267S and A379V variants are carried by roughly 45 percent of the population and significantly impair the conversion efficiency. People with these variants convert beta-carotene to retinol at 50% to 80% of the normal rate, meaning you could eat orange vegetables until they turn you orange and still be vitamin A deficient at the cellular level.

You experience this as poor night vision, frequent infections, slow wound healing, rough or hyperkeratotic skin, and reproductive issues. Your eyes can’t synthesize the visual pigment rhodopsin without adequate retinol. Your immune cells can’t differentiate properly. Your skin barrier weakens.

FUT2 encodes a fucosyltransferase that determines what carbohydrates your gut epithelial cells secrete into the mucus layer. This sounds obscure, but it’s critical: your microbiome composition depends on FUT2. Different gut bacteria strains thrive on different carbohydrate structures. FUT2 determines which strains dominate your microbiome, which in turn determines which vitamins and minerals your bacteria produce, whether your gut barrier stays tight or becomes leaky, and how well you absorb minerals across the intestinal wall.

FUT2 variants are extremely common, with roughly 45 to 60 percent of the global population carrying at least one copy of the non-secretor allele. Non-secretors have drastically different microbiome composition, reduced production of short-chain fatty acids (which power gut epithelial cells), and measurably reduced absorption of minerals including iron, zinc, and magnesium.

You notice this as mineral deficiencies that don’t respond to supplementation, bloating, irregular digestion, recurrent infections, and low energy. Your gut lining may be compromised. Your microbial-derived vitamins (B12, K2, folate) aren’t being produced. Mineral absorption pathways are depressed.

COMT encodes catechol-O-methyltransferase, the enzyme that breaks down dopamine, norepinephrine, and epinephrine. COMT also requires magnesium as a cofactor to function; every time COMT metabolizes a catecholamine, it uses magnesium. COMT variants therefore create a vicious cycle: if COMT is slow, catecholamines accumulate and you burn through magnesium even faster trying to process them. If COMT is fast, you metabolize dopamine and norepinephrine too quickly and also deplete magnesium trying to keep up.

The Val158Met variant is carried by roughly 40 to 50 percent of the population. People with the fast COMT variant (Met/Met) clear catecholamines rapidly but are extreme magnesium users and often develop magnesium-dependent symptoms including muscle tension, migraines, sleep disruption, and anxiety despite adequate dietary magnesium.

You experience this as magnesium-responsive symptoms (muscle cramps, tension, migraines, restless sleep) or conversely as dopamine-depletion symptoms (low motivation, poor focus, mood flatness) depending on your COMT direction. Your nervous system and muscles are competing for available magnesium. Your neurotransmitter metabolism is chronically destabilized.