What it does: It enables the absorption of calcium from food, supports bone density and strength, contributes to proper muscle contraction, and is involved in healthy immune function.
How it is used: Often taken to support bone health, boost immune defenses, address vitamin D deficiency, and help maintain muscle strength, especially in those with limited sun exposure or restricted diets.
Natural sources and supplement forms: The body produces vitamin D naturally when the skin is exposed to sunlight. Dietary sources include fatty fish, egg yolks, liver, and fortified foods. Supplements are available mainly as vitamin D3 (cholecalciferol), the more bioavailable form, and D2 (ergocalciferol).
Why it appears in supplement formulas: It is added to formulas to help keep bones strong and maintain healthy immune function, particularly valuable for people at risk of low vitamin D levels due to lifestyle, geography, or age.
What to know before use: Overuse or very high doses can cause blood calcium imbalances; individuals with health conditions or those taking certain medications should consult a healthcare provider before starting supplementation.
Vitamin D: The Sunshine Nutrient
Vitamin D is often called the 'sunshine vitamin' because your body can produce it when your skin is exposed to sunlight. Few foods naturally contain vitamin D; fatty fish like salmon, and fortified milk or cereal are primary dietary sources. This is why vitamin D is commonly included in supplements—to help people maintain adequate levels, especially in regions with limited sunlight.
