Vitamins D3 and K2: Their cooperation acts against osteoporosis

We have covered the topic of osteoporosis in a previous article and discussed bone health quite a bit. However, it is quite a major issue, which affects the lives of millions of people worldwide. That's why we decided today to focus on the vitamins that can play a key role in preventing as well as slowing down the disease!

And the reason is vitamins D3 and K2!

But first, let's remember what osteoporosis is...

Osteoporosis is a widespread disease of the skeletal system that affects a large percentage of humanity, and more specifically post-menopausal women and older people. To prevent and treat the disease, a balanced diet is recommended, focusing on calcium-rich foods, exercise and, if necessary, additional supplementation with nutritional supplements.

Osteoporosis, then, is characterised by reduced bone density (bone mass) and a disturbance in the structure of bone tissue, which is made up of type I osteocytes and collagen. Bones by nature are created to provide maximum strength for less body weight. During development, there is a normal balance between bone resorption and bone formation, leading to the creation of a normal and strong skeleton. As a result, bones tend to be more fragile with a high risk of fractures especially in the vertebrae in cases of increased body weight.

Osteoporosis is divided into primary and secondary. What? Did you think that osteoporosis only affects older people? In the first case, which is the most common, it occurs mainly in older people and in post-menopausal women. In the second case, it is the result of an underlying disease or medication use that affects bone metabolism and can occur at any age and gender.

Osteoporosis & prevention: How can I prevent it?

Prevention of osteoporosis is very important, as osteoporosis can directly affect a person's quality of life. By keeping bones in a healthy condition it can easily be prevented. But how?

A diet rich in vitamin D and calcium.
Exercise to enhance bone resilience.
Reduce excessive consumption of alcohol & salt.
Avoiding smoking.
Hormonal balance (maintaining estrogen and androgen at normal levels helps maintain bone density).
Timely medical monitoring and control, especially during menopause, menopause and afterwards.

Vitamin D3: The vitamin of the sun

Also known as cholecalciferol, it is a fat-soluble vitamin that has a major role in regulating calcium and phosphorus, contributing to bone health and the immune system.

Its main benefits are:

Calcium absorption
Immune health
Healthy musculoskeletal function
Support healthy psychological function
Reduction of inflammation and exhaustion

Vitamin D3: What are the best sources?

Solar radiation: It is synthesized in the skin through exposure to the sun.
Food: Rich sources include oily fish, egg yolk and dairy products.
Dietary supplements: when there is a deficiency or lack, our daily routine does not allow us to be exposed to the sun regularly.

Vitamin D3: What are the normal values & how much should I take?

Human needs are influenced by many factors including but not limited to age and daily living conditions. Decreased intake of vitamin D3 in the long term can lead to health problems. Regarding normal vitamin D3 values, adequacy in children ranges between 30-50 ng/mL and in adults 30-80 ng/mL. Age-independent deficiency is defined between 20-30 ng/mL and deficiency between 10-20 ng/mL with <10 ng/mL being classified as severe deficiency.

Supplementation consists of the following dosages:

Children 1-3 years of age may receive 600 I.U. (15μg)/day.
Children 4-10 years of age may receive 600-1,000 I.U. (15-25μg)/day.
Adults >19 years of age may receive 1,000-2,000I.U. (25-50μg)/day.
Pregnancy and lactation: women may receive 2,000I.U. (50μg)/day.
Menopause: women may take 1,000-2,000I.U. (25-50μg)/day.
Elderly >75 years of age can take 2,000-4,000 I.U. (50-100μg)/day.

Vitamin D3 & Osteoporosis: Can it help?

Vitamin D3 plays a key role in the prevention and treatment of osteoporosis, as it is essential for calcium absorption and maintaining bone density. Inadequate intake or synthesis can lead to secondary hyperparathyroidism with increased bone loss and increased risk of fractures. Its combination with calcium and exercise may help prevent and slow down the disease.

Vitamin K2: The "guide" of calcium

Vitamin K, like A, D and E, belong to the family of fat-soluble vitamins, i.e. vitamins that are stored in the liver and absorbed with the cooperation of fat (hence their name). Vitamin K has two subtypes, K1 (phylloquinone) and K2 (menaquinone). K2 compared to the other forms of K is the most well absorbed by the human body. Research recommends that 100-200mcg daily is a sufficient amount for health benefits along with Vitamin D3 for better calcium breakdown. K2 is found in the following two forms:

MK-4 (menaquinone-4), which is found in animal products such as liver, eggs and butter.
MK-7 (menaquinone-7), which comes from fermented foods such as natto (Japanese food made from fermented soybeans) and certain cheeses such as camembert, gouda and edam. This form has a longer shelf life in the body and is therefore more effective.

Vitamin K2 & Benefits:

Bone health, as it helps activate proteins that promote calcium breakdown in the bones.
Cardiovascular health, as it prevents calcium build-up in the arteries, reducing the risk of cardiovascular disease.
Dental health, helping to strengthen tooth structure through calcium regulation.

Vitamin K2 & Osteoporosis: Does it ultimately have a positive effect?

Vitamin K2, is a product vital to bone health as it works with vitamin D and calcium to maintain bone density at normal levels and prevent the onset of osteoporosis. Through the activation of osteocalcin (a protein that binds calcium to bone) it directs calcium and improves the condition of bone mass. Knowing that osteoporosis is a condition that affects the healthy bone condition, it is vitamin K2 that will act as a regulator of the pathway of other nutrients so that they are directed and function properly for the purpose of prevention and treatment.

Conclusion

The combination of vitamin D3 together with vitamin K2 is the ideal combination to support normal bone density. More specifically, D3 enhances calcium absorption, while K2 ensures that calcium is transported to the bones rather than to the arteries and tissues.

Holland and Barrett has a wide range of products that can be an ally in supporting against osteoporosis, including complete formulas to boost bone health, as well as calcium, vitamin D3, vitamin K2 supplements and combinations of these, so that the right product can be selected based on the unique needs of each individual.

"The better to cure, the better to prevent" Hippocrates had said and the case of osteoporosis could not be an exception.

Scientific references

FOUNDATION, I. O. (2025). Osteoporosis. INTERNATIONAL OSTEOPOROSIS FOUNDATION.

Halder, M., Petsophonsakul, P., Cengiz Akbulut, A., Pavlic, A., Bohan, F., Anderson, E., . . . Schurgers, L. (2019, February 19). Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease. International Journal of Molecular Sciences.

Health, N. I. (2024, July 26). Vitamin D. NIS.

Voulgaridou, G., K. Papadopoulou, S., Detopoulou, P., Tsoumana, D., Giaginis, C., S. Kondyli, F., . . . Pritsa, A. (2023, February 8). Vitamin D and Calcium in Osteoporosis, and the Role of Bone Turnover Markers: A Narrative Review of Recent Data from RCTs. MDPI.