Vitamin D has a significant impact on immune system function, helping to regulate it and supporting its ability to fight infection. It is known for its effect on the function of T lymphocytes and macrophages, which are key cells in the body's defense against pathogens. Vitamin D supports the ability of T lymphocytes to recognize and attack foreign microorganisms and helps macrophages to engulf and destroy pathogens.

Studies^1,2 have shown that people with adequate levels of vitamin D are less prone to infections such as the flu, the common cold and other viral and bacterial infections. Vitamin D also supports the production of antimicrobial peptides, such as cathelicidin, which have the ability to kill bacteria, viruses and fungi.

In addition, vitamin D plays a role in the prevention of autoimmune diseases, such as multiple sclerosis, rheumatoid arthritis and type 1 diabetes, by regulating the immune response and preventing excessive inflammatory reactions^3,4,5,6.

Vitamin D plays an important role in cardiovascular health by regulating blood pressure, heart function and blood vessel health. Vitamin D affects the renin-angiotensin-aldosterone (RAA) system, which controls blood pressure and fluid balance in the body. By inhibiting renin activity, vitamin D can help prevent hypertension.

In addition, vitamin D has anti-inflammatory properties that help protect blood vessels from inflammation, which can lead to atherosclerosis - the buildup of fatty plaques on the walls of blood vessels, which in turn can lead to heart attacks and strokes.

Vitamin D deficiency is associated with an increased risk of heart disease, including heart failure, coronary heart disease and cardiac incidents. Studies suggest that people with low vitamin D levels are more likely to develop hypertension and have poorer cardiovascular-related health outcomes^12,13.

People with limited sun exposure

• Residents of regions with low sun exposure: People living in northern latitudes where there is little sunlight in winter.
• Office workers: People who spend most of their time indoors and rarely go outside.
• People who wear clothing that covers most of the body: Wearing clothing that covers the skin for religious, cultural or health reasons can reduce vitamin D synthesis.

Elderly people

• Reduced synthesis capacity: As we age, the skin loses its ability to effectively synthesize vitamin D when exposed to sunlight.
• More time spent indoors: Older people often spend more time indoors or in care facilities.

People with darker skin

• Melanin in the skin: People with darker skin have more melanin, which reduces the skin's ability to produce vitamin D when exposed to UVB rays.

Pregnant and breastfeeding women

• Increased demand: Pregnant and breastfeeding women need more vitamin D for themselves and their baby. Vitamin D deficiency in the mother can lead to deficiency in the baby.

People with certain medical conditions

• Chronic diseases: People with diseases such as celiac disease, Crohn's disease, cystic fibrosis and other disorders that affect fat absorption may have difficulty absorbing vitamin D.
• Osteoporosis and other bone diseases: Vitamin D supplementation is often recommended for the treatment and prevention of osteoporosis.

People who are overweight or obese

• Vitamin D storage in adipose tissue: People who are overweight or obese may need higher doses of vitamin D because it is stored in fat tissue, reducing its availability in the body.