Vitamin D Deficiency — More Common Than You Think

42% of US adults are vitamin D deficient. Learn how this 'sunshine vitamin' affects energy, mood, immunity, and what to do about it.

Key Findings

Key Nutrients

The Bottom Line

Vitamin D isn't just a vitamin — it functions as a hormone that influences hundreds of genes. If you live north of the 37th parallel, work indoors, or have darker skin, you're almost certainly not getting enough from sunlight alone. Testing your levels and supplementing accordingly (with K2 and magnesium) is one of the highest-impact health interventions available.

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