You've likely heard of the "sunshine vitamin," but are you familiar with how your body synthesizes it? Vitamin D is essential for bone health, strength, and hormonal balance. It also supports a healthy immune system. Read on to find out more.
Bone Support
Without sufficient Vitamin D, your bones may become brittle and more likely to break. Vitamin D is vital for absorbing and retaining calcium and phosphorus—both essential minerals for building bone and maintaining its integrity. Because Vitamin D is fat-soluble, it is better absorbed when consumed with a fat source.
Hormonal Balance
Vitamin D is essential for hormone regulation, aiding in the production of parathyroid hormone (PTH) for maintaining calcium balance, influencing insulin levels for blood sugar control, and supporting the synthesis of sex hormones such as estrogen and testosterone. It also helps the adrenal glands produce cortisol, which is crucial for stress response and energy metabolism.
Can Be Synthesized by the Skin
Regular exposure to sunlight allows your body to synthesize Vitamin D. Experts support 10-30 minutes of midday sunlight a few times per week for optimal blood levels; however, exposure times may vary depending on the melanin in your skin.
Vitamin D3 & K2: Better Together
While Vitamin D3 helps your body absorb calcium, Vitamin K2 plays the crucial role of directing that calcium to the right places (like your bones and teeth) while keeping it out of soft tissues like your arteries. Without enough K2, all that absorbed calcium could end up in the wrong places, which isn’t all that great for long-term health.
Think of D3 as the delivery truck, and K2 as the traffic controller—guiding calcium to where it’s actually needed.
K2 is found in foods like aged cheeses, egg yolks, grass-fed butter, and fermented foods (like natto), but it’s not as easy to get in high amounts through diet alone, especially in standard Western diets.
If you’re supplementing with D3 consistently, consider talking with your healthcare provider about whether K2 should be part of your routine, too.
The Daily Dose
Research suggests that adults who want to maintain optimal levels of Vitamin D should aim for a daily intake of 800-2000IU. Look to whole-food sources such as wild-caught fatty fish, grass-fed butter, liver, egg yolks, and mushrooms—and fill in any gaps with high-quality supplementation.