Strom Sports Vitamin D3 & K2 90 Caps

Strom Sports Vitamin D3 & K2 – High-Strength Daily Support for Bones, Immunity & Cardiovascular Health

Vitamin D deficiency is one of the most widespread nutritional shortfalls in the UK and across the Northern Hemisphere — with estimates suggesting that over 40% of the adult population has insufficient levels, rising significantly during the autumn and winter months when sunlight exposure drops below the threshold needed for meaningful skin synthesis.

The consequences of deficiency are broad and well-documented: impaired immune function, reduced bone density, low mood, hormonal disruption, poor recovery from exercise, and increased risk of a range of chronic conditions. For athletes and active individuals — who place greater physiological demands on the body and whose immune and musculoskeletal systems are under constant stress — optimal vitamin D status is not optional. It's foundational.

Strom Sports Vitamin D3 & K2 delivers a high-strength 5,000 IU (125µg) of Vitamin D3 as cholecalciferol — the most bioavailable form — paired with 125µg of Vitamin K2 as MK-7, the longest-acting and best-absorbed form of K2 available. Together, they form one of the most synergistic and clinically credible pairings in all of nutritional supplementation.

A full 90-capsule, three-month supply — consistent with the Strom Raw philosophy of quality, effectiveness, and transparency.

Key Benefits

Bone Health & Skeletal Strength

Vitamin D3 is essential for calcium absorption in the gut — without adequate D3, the body cannot absorb calcium efficiently regardless of dietary intake or supplementation. This makes D3 a critical upstream factor for bone mineralisation and skeletal integrity. However, increasing calcium absorption without directing that calcium appropriately creates a problem: excess calcium can accumulate in arteries and soft tissue rather than being deposited in bone where it belongs.

This is where K2 becomes indispensable. Vitamin K2 activates two critical proteins — Osteocalcin and Matrix Gla-Protein (MGP) — that together direct calcium to bone tissue and actively remove calcium from arterial walls. K2 doesn't just complement D3; it completes the calcium regulation cycle that D3 initiates. Without K2, high-dose D3 supplementation can actually increase cardiovascular risk through calcium dysregulation. With K2, that risk is managed and the benefits to bone density are maximised.

Immune System Support

Vitamin D receptors are present on virtually every cell of the immune system — a strong indication of how central D3 is to immune regulation. Research has consistently associated optimal vitamin D status with reduced susceptibility to respiratory infections, improved innate and adaptive immune responses, and reduced severity of inflammatory conditions. For athletes whose intense training temporarily suppresses immune function, and for anyone managing the demands of a busy modern lifestyle, maintaining replete D3 levels provides a meaningful immune defence advantage.

Muscle Function & Athletic Performance

Beyond bone and immunity, vitamin D plays a direct role in muscle function. D3 receptors are found in muscle tissue, and research has associated vitamin D deficiency with reduced muscle strength, impaired neuromuscular function, and increased risk of injury. Studies in athletes have linked higher vitamin D status with improved strength, power, and reaction time — with meaningful performance differences observed between deficient and replete individuals even at the elite level.

Cardiovascular Protection

K2 as MK-7 is one of the most cardiovascularly protective nutrients in the supplement world. The Matrix Gla-Protein (MGP) activated by K2 is the body's most potent inhibitor of arterial calcification — a key driver of cardiovascular disease. Clinical studies, including the Rotterdam Study involving nearly 5,000 participants over 10 years, have associated higher dietary K2 intake with significantly reduced arterial calcification, lower cardiovascular mortality, and reduced risk of coronary heart disease. At 125µg of MK-7 per capsule, Strom's formula delivers a clinically meaningful dose.

Mood, Cognitive Function & Hormonal Health

Vitamin D3 plays an important modulatory role in the synthesis of serotonin and dopamine — the neurotransmitters central to mood regulation, motivation, and cognitive performance. Deficiency is consistently associated with increased risk of depression, low mood, and cognitive decline. D3 also plays a role in testosterone production, with studies in deficient men showing meaningful improvements in testosterone levels following D3 supplementation — a benefit of particular relevance to active males.

Why Vitamin K2 as MK-7 Specifically?

Not all K2 is equal. Vitamin K2 exists in several forms — the most common in supplements being MK-4 and MK-7. The difference is significant:

• MK-4 has a biological half-life of just 1–2 hours, meaning it is metabolised and cleared from the body rapidly. Multiple high doses throughout the day are required to maintain meaningful blood levels
• MK-7 (menaquinone-7) has a half-life of approximately 72 hours (3 days), meaning a single daily dose maintains consistent, elevated K2 levels in the bloodstream throughout the entire day and beyond

MK-7 is also significantly better at activating the key carboxylation-dependent proteins (Osteocalcin and MGP) than MK-4, making it the superior form for both bone and cardiovascular applications. Strom Sports' use of MK-7 at 125µg reflects a commitment to clinical efficacy over cost-cutting — and at this dose, the formula aligns with the amounts used in the most significant human clinical trials.

Why 5,000 IU of Vitamin D3?

The UK government recommends 400 IU of vitamin D daily for the general population — a baseline established to prevent severe deficiency rather than to achieve optimal physiological levels. For many individuals, particularly those with limited sun exposure, darker skin tones, higher body weight, or active lifestyles that increase D3 demand, 400 IU is insufficient to raise and maintain serum 25(OH)D to the levels associated with optimal health outcomes.

Research suggests that serum 25(OH)D levels of 40–60 ng/mL are associated with optimal health outcomes — levels that typically require significantly higher daily intake than standard low-dose supplements can deliver. A 5,000 IU (125µg) daily dose is widely used in clinical practice and research settings to raise and maintain levels in this optimal range in deficient or insufficient individuals.

Note: We recommend getting your vitamin D levels tested before beginning high-dose supplementation, and consulting your healthcare professional if you have any existing medical conditions or are taking medications that may interact with vitamin D.

Why Choose Strom Sports Vitamin D3 & K2?

• 5,000 IU (125µg) Vitamin D3 — high-strength cholecalciferol for meaningful replenishment and optimal serum levels
• 125µg Vitamin K2 as MK-7 — the longest-acting, most bioavailable form for full-day calcium regulation and cardiovascular protection
• D3 and K2 work synergistically — K2 completes the calcium cycle that D3 initiates, making the combination safer and more effective than either alone
• Clinically meaningful doses — both ingredients dosed at levels consistent with published human research
• 90 capsules — a full three-month supply — consistent daily supplementation at outstanding value
• One capsule per day — simple, no-fuss daily habit
• Cholecalciferol (D3) not ergocalciferol (D2) — the natural, more potent form that raises serum 25(OH)D levels significantly more effectively
• Consistent with the Strom Raw philosophy — no unnecessary additives, no fillers, just what's needed at the right dose

How to Use

Take 1 capsule daily with a meal containing dietary fat — D3 and K2 are both fat-soluble vitamins and absorb significantly better alongside a fat-containing meal.

• Take with your largest meal of the day for maximum absorption — breakfast, lunch, or dinner all work
• Consistency is key — fat-soluble vitamins build up in the body over time; daily supplementation is far more effective than sporadic high doses
• Do not exceed 1 capsule per day unless advised by a healthcare professional
• If you are also supplementing with additional calcium, inform your doctor — D3 and K2 both influence calcium metabolism
• Store in a cool, dry place away from direct sunlight

Who Is It For?

Strom Sports Vitamin D3 & K2 is ideal for:

• Anyone living in the UK, Northern Europe, or any region with limited year-round sunlight exposure
• Gym-goers and athletes who want to support muscle function, strength, recovery, and immune resilience
• Those concerned about long-term bone density and skeletal health
• Anyone who wants to support cardiovascular health and protect against arterial calcification
• Those who have been diagnosed with or are at risk of vitamin D deficiency
• People who work indoors, cover their skin for cultural or occupational reasons, or otherwise have limited daily sun exposure
• Anyone already taking high-dose D3 who wants to ensure they are also taking K2 to properly direct the calcium D3 mobilises
• Those looking for a clean, high-quality D3/K2 supplement without unnecessary additives or fillers

The Result

Stronger bones. Sharper immunity. Better muscle function. Protected arteries. More stable mood and energy. And the confidence of knowing your vitamin D and K2 levels are being maintained at a dose that actually makes a difference.

Vitamin D and K2 are not optional for anyone serious about long-term health. Strom Sports makes sure you're getting both — at the right dose, in the right forms, with nothing wasted.

One capsule. Three months. Foundational health support done properly.

Supplement Facts

*NRV = Nutrient Reference Value. Serving size: 1 capsule. Servings per container: 90 (3-month supply).

Ingredients

Vitamin D3 (Cholecalciferol) 125µg, Vitamin K2 (Menaquinone-7) 125µg, capsule shell (HPMC).

For allergens, see ingredients in bold. Produced in a facility that handles Milk, Soy, Egg, and Gluten.

Warnings: Do not exceed the recommended daily dose. Consult your physician prior to use, especially if you have a medical condition or are taking medication — particularly anticoagulants such as warfarin, as Vitamin K2 may interact with blood-thinning medications. Not recommended for anyone under the age of 18. Do not take if pregnant or breastfeeding. This product is not intended to diagnose, treat, cure, or prevent any disease or illness and should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Keep out of reach of children. Store in a cool, dry place.