Sunlight Conversion Efficiency
Some people make plenty of vitamin D from 15 minutes of sun; others barely budge after an hour at the beach. Your gene variant predicts whether you're solar-powered or supplement-dependent—no more guessing.
What this measures
How your DNA shapes sunlight conversion efficiency.
DHCR7 codes for 7-dehydrocholesterol reductase — the enzyme that competes with sunlight for the precursor that becomes vitamin D in skin. Higher DHCR7 activity diverts more of the precursor to cholesterol synthesis; lower activity leaves more available for UVB conversion to vitamin D3. NADSYN1 sits alongside in the same pathway.
Carriers of common DHCR7 variants are associated with anywhere from typical sunlight-to-vitamin-D conversion to reduced efficiency — and the same sun exposure produces different vitamin D output across variant patterns. Skin pigmentation, age, and latitude all stack with the variant effect. By age 70, the same UV dose produces roughly a quarter of the vitamin D it did at age 20.
Latitude above ~37°N essentially eliminates UVB-driven vitamin D synthesis from October through March in most clients. Sunscreen blocks the conversion entirely (which is fine — UVA exposure carries the cancer risk, not the vitamin D production). Magnesium is required to activate the vitamin D made; deficiency stalls the pathway downstream of UVB.
The "I get plenty of sun" client and the "I work indoors" client are often closer in serum vitamin D than either expects. Which DHCR7 variant you carry — and where you live — decides whether sunlight is a meaningful vitamin D source or whether oral supplementation is the lever that actually moves levels.
Sunlight Conversion Efficiency is one specific finding in this system. Your Genomic Lifestyle Optimization Report shows where your variants place you on the micronutrients and strategic supplementation spectrum — and what you can do about it.
In your report
Where Sunlight Conversion Efficiency lives inside your Genomic Lifestyle Optimization Report.
Sunlight Conversion Efficiency renders as a dark-background card with a color marker calibrated to your specific variants. The card opens with the gene mechanism, shows your result at a glance via that marker, and closes with a practical, mechanism-led recommendation — what to eat, what to time, what cofactors to support.
Want to see what a real Mosaic dark card looks like? Walk through a sample report →
In context
Fat-Soluble Vitamins: the 7-insight cluster.
Sunlight Conversion Efficiency is one finding in a tightly-related cluster. Mosaic sequences the other 6 alongside it so you see the whole biology — not an isolated data point.
- Reliability of Vitamin D TestingSome people show "normal" blood levels but still have functional vitamin D deficiency at the tissue level. Your receptor and transport variants tell you whether standard testing reflects your status—or just looks like it does.
- Vitamin A Conversion EfficiencyBeta-carotene to active retinol conversion can be 10–20× less efficient in some people. If you're a poor converter, no amount of carrots will give you adequate vitamin A—you need preformed sources like liver or cod liver oil for vision, immunity, and skin.
- Vitamin D Intake NeedsThe dose required to reach optimal blood levels ranges from 1,000 to 10,000 IU daily between different people. Your receptor and binding-protein variants tell you exactly where you land—no more trial-and-error supplementation.
- Vitamin E Inflammation PropensityHigh-dose vitamin E lowers inflammation in most people—but raises it in a genetic minority. Knowing your response prevents the difference between a helpful supplement and one that's quietly making things worse.
- Vitamin E Intake NeedsCell-membrane protection needs vary. Higher-need individuals benefit from mixed tocopherols and tocotrienols—not just the alpha-tocopherol in most supplements. Your result tells you whether basic coverage is fine or you need the full spectrum.
- Vitamin K Intake NeedsK1 to K2 conversion efficiency determines whether leafy greens alone keep calcium in bones and out of arteries. Poor converters need fermented foods or K2 supplements—otherwise, the greens aren't doing what you think.
Questions people ask
About Sunlight Conversion Efficiency.
- How does my DNA influence sunlight conversion efficiency?
- Where vitamin meets variant: the MTHFR methylation cycle (folate), the GC/CYP2R1/VDR vitamin-D activation pathway, the TMPRSS6/HFE iron-handling network, and the genes that determine which forms of B12, magnesium, and choline your body actually absorbs versus ignores.
- What kind of test do I need to see my Sunlight Conversion Efficiency result?
- Whole-genome sequencing at 30× clinical depth. Consumer SNP-chip tests like 23andMe or AncestryDNA only read ~0.02% of your DNA and miss most of the variants this analysis needs. Mosaic reads all 3 billion base pairs and produces the full 108-insight report.
- How is Sunlight Conversion Efficiency different from clinical lab testing?
- Clinical labs measure downstream biomarkers — blood levels, hormone values, metabolic byproducts — at a single point in time. Genomic insights like Sunlight Conversion Efficiency reveal the underlying variant that shapes the biology, which is constant for life. The two are complementary: labs show the current snapshot; genomics shows the long-term tendency and where lifestyle leverage is highest.
More from Micronutrients and Strategic Supplementation
micronutrients and strategic supplementation
Blood Pressure Sensitivity to Sodium Intake
About half of people see their blood pressure rise with salt; the other half are neutral. This decides whether low-sodium is medically mandatory or an unnecessary restriction that just makes food taste worse.
Read insight →micronutrients and strategic supplementation
Choline Intake Needs
Choline demand varies 2–3× between people. Higher-need individuals see noticeable improvements in focus, fat metabolism, and liver function from eggs or supplementation—while others coast fine without thinking about it.
Read insight →micronutrients and strategic supplementation
Copper Levels
Copper is a behind-the-scenes player—affecting iron absorption, collagen production, and antioxidant defense. The catch: both deficiency and excess cause problems, and they look surprisingly similar. Your regulation pattern tells you which direction to watch.
Read insight →micronutrients and strategic supplementation
FUT2 Status
"Non-secretor" status changes how you absorb B12 and shapes your gut microbiome. This explains why some vegetarians stay healthy for decades while others crash within years—same diet, very different biology.
Read insight →micronutrients and strategic supplementation
Folate Intake Needs
Folate requirements vary widely—especially during pregnancy, high stress, or rapid cell turnover. Knowing yours prevents the subtle deficiency that quietly affects mood, energy, and long-term health without obvious symptoms.
Read insight →micronutrients and strategic supplementation
Folic Acid Conversion Efficiency
Common variants reduce the conversion of synthetic folic acid (in supplements and fortified foods) into active methylfolate. If you're affected, standard prenatals and "enriched" bread aren't doing what you think. Methylfolate does.
Read insight →
One test. 108 personalized findings. All yours.
Order your Mosaic kit. Receive your raw genomic data and the full Genomic Lifestyle Optimization Report in 15–20 days.