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How does UVB radiation activate vitamin D?

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
UVB activates vitamin D through cholesterol. That's why your blood cholesterol levels rise in the winter. Because of the lack of sunlight, you don't have enough active vitamin D in winter, so your body pumps up your cholesterol in the hope of converting as much as possible to active vitamin D.

This serves as another example of an evolutionary trade-off between procreation and longevity. To protect us from deficiencies of vitamin D, we've evolved to have higher levels of cholesterol. So now we survive to mate and to be able to stand up strong and look good—only to be felled by high LDL cholesterol and consequent heart disease and stroke.
You: Staying Young: The Owner's Manual for Extending Your Warranty

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You: Staying Young: The Owner's Manual for Extending Your Warranty

International bestselling authors of YOU: The Owner's Manual and YOU: On a Diet give you all the tools and know-how to stay young and defy the ageing process. Drawing lively parallels between your...

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.