Vitamin D3 5,000 IU (125 mcg): Strong Immunity, Healthy Bones & Muscles, Inflammatory Balance & Well-Being Support

Vitamin D3, 125 mcg (5,000 IU), Life Extension is a concentrated dietary supplement formulated to provide vitamin D3 (cholecalciferol) – 125 µg (625% NRV), one of the most important vitamins with hormone-like activity in the body. Although it is called a “vitamin,” vitamin D3 acts as a complex metabolic regulator, influencing the expression of numerous genes involved in immunity, bone health, muscle function, and inflammatory balance. In the context of modern lifestyle—long periods spent indoors, reduced sun exposure, and pronounced seasonality—vitamin D levels are often suboptimal, and supplementation can become essential support for maintaining vital functions.

Vitamin D3 is the biologically preferred form produced in the skin under the action of UVB rays. After synthesis or ingestion, vitamin D undergoes transformations in the liver and kidneys, becoming the active form that binds to specific receptors (VDR) present in many tissues. These receptors are found not only in bones, but also in the immune system, muscles, brain, vascular endothelium, and other key structures, which explains its broad impact on overall health.

D3 is essential for efficient absorption of calcium and phosphorus, maintaining bone mineral density and supporting skeletal structure. At the same time, it contributes to normal muscle function, maintaining strength and coordination—important both for active individuals and for older adults. Another central role is immune modulation: vitamin D supports innate immunity (the first line of defense) as well as balanced adaptive immunity, helping promote an effective yet controlled response.

With its 5,000 IU dose, this formula is intended especially for people seeking robust support of vitamin D levels, particularly during periods of reduced sun exposure or in the context of increased physiological needs. Life Extension’s Vitamin D3 stands out through its simple formula, high concentration, and focus on fundamental functions: immunity, bones, muscles, and metabolic balance.

Detailed Benefits of Vitamin D3 5,000 IU (cholecalciferol)

• Supporting Immunity and Natural Defense Mechanisms

The immune system needs precise signals to respond effectively to environmental challenges. Vitamin D3 influences the activity of immune cells, including macrophages and dendritic cells, supporting the body’s ability to respond quickly and coherently. At the same time, vitamin D is involved in maintaining immune response balance so that reactions are appropriate and well controlled.

Against a background of stress, fatigue, insufficient sleep, or the cold season, consistent nutritional immune support becomes even more important.
✅ Support for innate immunity – the first protective barrier
✅ Support for balanced adaptive immunity
✅ Maintaining an effective and controlled immune response

Through these effects, vitamin D3 is considered one of the most valuable vitamins for long-term immune support.

• Bone Health and Maintaining Mineral Density

One of the best-known roles of vitamin D3 is facilitating the absorption of calcium and phosphorus from the intestines. Without adequate vitamin D, even a calcium-rich diet may be poorly utilized, and the body may mobilize calcium from bones to maintain mineral balance in the blood.

Vitamin D3 therefore contributes to maintaining bone density and the structural strength of the skeleton—key aspects for preventing bone fragility with age.
✅ Optimized absorption of calcium and phosphorus
✅ Support for bone mineralization and structural strength
✅ Long-term maintenance of skeletal integrity

This benefit is relevant both for sedentary individuals and athletes, since the skeleton is the foundation of stability and physical performance.

• Muscle Function, Strength, and Coordination

Vitamin D receptors also exist in muscle tissue, and vitamin D3 is involved in normal muscle fiber function, strength, and neuromuscular control. Optimal vitamin D levels can support muscle tone, endurance, and recovery, making it important for mobility and stability.

For active individuals, vitamin D3 may help maintain physical performance, and for older adults it may support coordination and everyday functional capacity.
✅ Support for normal muscle function and efficient contraction
✅ Support for maintaining strength and mobility
✅ Support for coordination and stability

Vitamin D3 thus becomes a foundational nutrient for keeping the body strong and functional.

• Inflammatory Balance and Support for Systemic Health

Low-grade chronic inflammation is a factor that can accelerate biological aging and affect multiple body systems. Vitamin D3 helps modulate inflammatory responses by influencing immune signaling and mediators involved in internal balance processes.

This role is important in the context of a demanding lifestyle with high stress, an imbalanced diet, or sedentary habits, where the body needs steady support to maintain homeostasis.
✅ Support for a balanced inflammatory response
✅ Support for metabolic stability and long-term health
✅ Contribution to functional protection of tissues

From this perspective, vitamin D3 does not act on only one organ, but supports a “central regulation” of the body’s balance.

• Cardiovascular Support and Vascular Function

Vitamin D3 is associated with vascular health through the presence of VDR receptors in the endothelium and through its role in processes related to vascular tone and normal vessel wall function.

Although cardiovascular health is influenced by many factors (lifestyle, diet, physical activity), vitamin D is a foundational nutrient involved in maintaining normal regulatory systems.
✅ Support for vascular function and endothelial health
✅ Support for maintaining systemic balance involved in cardiovascular health
✅ Contribution to the body’s resilience against metabolic stress

This benefit is of interest especially to those seeking a comprehensive long-term health-support strategy.

• Well-Being, Energy, and Support for Neurocognitive Function

Vitamin D3 is linked to important neurological functions because its receptors are also present in the brain. Indirectly—by supporting immunity, inflammatory balance, and muscle function—vitamin D may contribute to better overall well-being: more stability, resilience, and adaptive capacity.

During periods with reduced natural light, when the body produces less vitamin D, maintaining levels can be relevant for general comfort and daily tone.
✅ Support for neurocognitive functions through vitamin D’s role in body regulation
✅ Support for stress adaptation and maintaining vitality
✅ Contribution to overall well-being balance

This 5,000 IU formula is designed for individuals seeking strong, consistent, and simple support of an essential nutrient with systemic impact.

• Essential Role in Long-Term Health Maintenance

Vitamin D3 sits at the intersection of immunity, bone, muscle, and internal regulation. This positioning makes it a “pillar” nutrient for long-term health.

Maintaining adequate intake supports resilience, recovery capacity, structural integrity, and protective functions.
✅ Support for healthy aging by maintaining key functions
✅ Functional protection for the most demanding systems: immune, skeletal, muscular
✅ Support for metabolic balance and homeostasis

Vitamin D3 5,000 IU, Life Extension is a concentrated, clean, results-oriented formula that emphasizes one of the body’s most important vitamins: vitamin D3 in its biologically active form (cholecalciferol), with a fundamental role in immunity, bones, muscles, and internal balance.



 

Directions for Use

Read the entire label and follow instructions carefully before use
Take one (1) softgel daily with food, or as recommended by a physician.



 

Other Ingredients

Extra virgin olive oil, gelatin, medium chain triglycerides,  glycerin, purified water, rosemary extract.

Warnings

Individuals consuming more than 50 µg (2,000 IU) of vitamin D per day (from diet and supplements) should periodically obtain a serum measurement of 25-hydroxy vitamin D. Do not exceed 10,000 IU per day unless your physician recommends doing so. Vitamin D supplementation is not recommended for individuals with high blood calcium levels.
Keep out of reach of children.
Do not exceed the recommended dose.
Do not purchase if the outer seal is broken or damaged
When using nutritional supplements, please consult your physician if you are undergoing treatment for a medical condition or if you are pregnant or nursing
Store tightly closed in a cool, dry place.