Vitamin D, explained

Automatically transcribed from the showcased film. Wording may contain errors. This is the client’s narration, not advice from FDM.

Right now, the summer sun is at its absolute peak. But despite all that heat and light, one billion people on Earth are starving for vitamin D. Just look at some of the sunniest places on Earth, like parts of Africa and Southeast Asia. You would expect their vitamin D deficiency rates to be zero. Instead, studies show that up to 70% to 80% of people in these regions are severely lacking it. How is this possible? Because the summer sun you think you are getting is actually a trick. Sunlight has two main types of rays-- UVA and UVB. Only the stronger UVB rays have the exact energy needed to enter your skin and create vitamin D. But standard window glass acts like a brick wall against UVB rays, completely blocking 100% of the vitamin D-making light. The UVA rays still pass through the glass, giving you a tan and a feeling of warmth. But your actual vitamin D production stays at zero. So you decide to beat the system. You wait until work ends at 6 PM, and you step outside into the bright evening sun to get your daily dose. At noon, when the sun is directly overhead, the path through the sky is at its shortest, allowing UVB to reach your skin. The best time to make vitamin D is strictly limited to peak midday hours. Usually between 10 AM and 2 PM. This gives us the shadow rule. If your shadow is taller than you are, the atmosphere has already filtered out the rays you need to make vitamin D. Modern humans spend up to 93% of their lives indoors. During hot summer days, we hide in air-conditioned buildings to escape the heat right during those peak midday hours, missing out on the only four hours of the day when our bodies can actually make vitamin D. This total lack of midday sun triggers a quiet but highly destructive crisis in your body. Because vitamin D is not just a regular vitamin, it is a powerful hormone that acts as the absolute gatekeeper for calcium. Every minute of every day, your blood needs calcium to send the electrical signals that keep your heart beating. Without vitamin D, your stomach is basically blind to calcium, absorbing only 10% to 15% of what you eat. With enough vitamin D, that number jumps up to 40%. When you spend your summer indoors, those gates close. Your blood calcium levels begin to dangerously drop. They flood your blood with a hormone called PTH, which makes a brutal choice. It saves your heart today by sacrificing your bones tomorrow. This hormone starts a literal bone heist. It commands bone-eating cells to attach to your skeleton. They release strong acids to rapidly dissolve your bones, dumping that stolen calcium back into your blood. Your skeleton is eaten away just to keep you alive. This continuous theft leads to weak, painful bones. We often hear about osteoporosis, where bones become brittle and break easily. But severe vitamin D starvation causes something entirely different. Osteomalacia. Osteomalacia is a problem with how your bones harden. Your body tries to build new bone tissue, but because you aren't absorbing calcium, this new tissue simply cannot harden. To pull an adult out of a severe deficiency, science shows you need about 4,000 to 5,000 units of vitamin D3 every day. But natural vitamin D is incredibly rare in human food. To hit that 5,000 unit target just by eating, you would need to drink 40 to 50 glasses of milk every single day, or eat over 110 egg yolks. Human beings are mathematically incapable of eating their way out of a severe vitamin D deficit. So what is the actual solution? If you want to make vitamin D naturally, you have to be outside at the exact right time. You need direct sun on your skin, strictly between 10 a.m. and 2 p.m. Remember the shadow rule? If your shadow is shorter than you are, the sun's rays can actually help you. If you can't stand under the blazing midday sun every day, you just need to bypass the system entirely. An oral supplement does exactly that. Something simple like a vitamin D tablet gives you the exact high potency dose of vitamin D3 you need, up to 5,000 units. This flips your stomach's gates back open and absorbs the calcium your bones desperately need. It's not magic, it's just basic biology. Take a supplement or go stand in the midday sun. But at least now you know why the evening summer breeze isn't saving your skeleton.