Sunlight
Video Notes
The sun is essential to life and health. It not only gives us light, warmth, and energy, but it is also the best source for Vitamin D (aka: The Sunshine Vitamin).
Medical studies estimate that over 40% of the population is Vitamin D Deficient.
When exposed to sunlight, a cholesterol-like compound in your blood is transformed to Vitamin D. Then it is converted to its active form by the liver and then by the kidneys.
Q1: Why do we need Vitamin D?
A: Vitamin D is important in 3 metabolic pathways:
As a vitamin:
As a steroid hormone:
As an antioxidant:
Many studies show that sun exposure is inversely correlated to cancer rates. More Sun = Less Cancer!
Except skin cancers, which are usually benign, detected early, treated effectively, and relatively rare.
Q2: How much sun exposure is enough?
A: Most people only need to spend “a short time” in the sun to maintain healthy Vitamin D blood levels.
Q3: What is the risk of getting too much exposure to sunlight?
A: There are two wavelengths of ultraviolet radiation (sunlight) to consider: UV-A and UV-B.
Q4: Does sunlight really make people happy?
A: Many people experience Seasonal Affective Disorder (SAD).
Bonus Q5: Can I get enough Vitamin D from the foods I eat?
A: It is very difficult to get enough Vitamin D from dietary sources, especially for vegetarians.
Review: Top 10 Health Benefits of adequate Sunlight/Vitamin D:
Medical studies estimate that over 40% of the population is Vitamin D Deficient.
When exposed to sunlight, a cholesterol-like compound in your blood is transformed to Vitamin D. Then it is converted to its active form by the liver and then by the kidneys.
Q1: Why do we need Vitamin D?
A: Vitamin D is important in 3 metabolic pathways:
As a vitamin:
- Vitamin D regulates blood calcium levels for maintaining bone health:
- Prevents Ricketts (soft bones) in children.
- Helps prevent Osteoporosis (thin/brittle bones) in older adults.
As a steroid hormone:
- Vitamin D modulates genes:
- Activates good (health-promoting) genes.
- Suppresses bad (disease-promoting) genes (oncogenes > cancer).
As an antioxidant:
- Vitamin D protects cells against free radicals:
- Free radicals are produced during digestion and from exposure to tobacco smoke or radiation.
- Free radicals play a role in heart disease, cancer, autoimmune disorders, and neurodegeneration.
Many studies show that sun exposure is inversely correlated to cancer rates. More Sun = Less Cancer!
Except skin cancers, which are usually benign, detected early, treated effectively, and relatively rare.
Q2: How much sun exposure is enough?
A: Most people only need to spend “a short time” in the sun to maintain healthy Vitamin D blood levels.
- One size does not fit all, but 10-30 minutes of sun exposure several times per week is probably sufficient for most people.
- Vitamin D production is influenced by season, time of day, latitude, altitude, clothing, skin pigmentation, sunscreen use, passage of light through glass or plastic, and age.
- Vitamin D is stored in the body during the summer months and is then made available during the winter months.
- Although fat soluble, there is essentially no risk of toxicity by sunlight.
- Extra Vitamin D is turned into inactive substances.
- Supplementation does pose a potential risk for toxicity.
Q3: What is the risk of getting too much exposure to sunlight?
A: There are two wavelengths of ultraviolet radiation (sunlight) to consider: UV-A and UV-B.
- UV-A radiation is mainly responsible for causing skin cancers.
- UV-B radiation activates Vitamin D in the skin, but also causes sunburn.
- Most sunscreens block UV-B radiation much more than UV-A radiation.
- Most sunscreens prevent sunburn, but also limit Vitamin D production.
- Most sunscreens do not provide much protection against skin cancer.
Q4: Does sunlight really make people happy?
A: Many people experience Seasonal Affective Disorder (SAD).
- SAD is a cyclic, usually milder, form of depression that occurs during the winter months.
- SAD can be very disabling: low energy, moody, frustrated.
- SAD is effectively treated using phototherapy (artificial sunlight).
- Phototherapy increases blood levels of Vitamin D and changes brain chemistry (serotonin).
- Natural sunlight (and being outdoors breathing fresh air) is ideal.
Bonus Q5: Can I get enough Vitamin D from the foods I eat?
A: It is very difficult to get enough Vitamin D from dietary sources, especially for vegetarians.
- Salmon, Sardines/herring, Cod liver oil, Canned tuna, Beef liver, Egg yolks, Mushrooms
- You would need to eat these nearly every day to get enough Vitamin D.
- Some foods are fortified with Vitamin D: Cow’s Milk, Plant Milks, Orange Juice, Cereals/Oatmeal
Review: Top 10 Health Benefits of adequate Sunlight/Vitamin D:
- Support better sleep (serotonin)
- Improve mood
- Increase energy
- Prevent depression (SAD)
- Prevent heart disease
- Prevent auto-immune disorders
- Reduce inflammation
- Prevent cancer (gene modulation)
- Strengthen bones
- Extend life expectancy
In achieving your goal of living to 120, getting adequate exposure to sunlight is an important habit that you should make part of your healthy lifestyle.
Vitamin D Supplementation?
Routine Testing and Supplementation of Vitamin D are NOT Recommended for Everyone.
- Lack of Strong Evidence: Many studies have failed to demonstrate significant health benefits of routine vitamin D testing and supplementation in healthy individuals.
- No Consensus on Optimal Levels: There's no universal agreement on the ideal vitamin D blood level, and some experts suggest that targeting levels above 30 ng/mL may not offer additional benefits for bone health. (Blood levels may not correlate with physiological functions of vitamin D).
- Potential Risks of Over-Supplementation: Taking excessive amounts of vitamin D can lead to hypercalcemia (high blood calcium levels) and other health problems.
- Focus on Risk Groups: Instead of widespread testing, healthcare professionals should focus on identifying and addressing vitamin D deficiencies in individuals at higher risk.
- Recommended Strategies: Ensure adequate sun exposure and consume foods that are fortified with vitamin D.
Notes & Worksheet
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