Harnessing the Combined Benefits of Vitamins D and K for Cardiovascular Health

Vitamins D and K are essential for maintaining bone health and regulating blood clotting. Recent research has highlighted the synergistic effects of these vitamins on cardiovascular health. Low levels of vitamins D and K have been associated with a higher risk of overall mortality compared to those with normal levels. This article explores the benefits of vitamins D and K for heart health.

What Is Vitamin K?

Vitamin K is a fat-soluble vitamin present in a variety of foods and available as a dietary supplement. It plays a key role in producing proteins essential for blood clotting. Some anticoagulant medications work by inhibiting the action of vitamin K, which prevents blood from clotting.

Vitamin K comes in two forms: K1 and K2. Vitamin K1 is mainly found in leafy green vegetables and serves as the primary dietary source of vitamin K. In contrast, vitamin K2 is found in animal-based foods and fermented products such as cheese and yogurt. Additionally, some vitamin K2 is produced by the bacteria in your gut.

Research indicates that vitamin K may help prevent the calcification of blood vessel walls, which can be beneficial in preventing atherosclerosis and supporting cardiovascular health. While vitamin K is stored in the liver and other tissues such as the brain, heart, and bones, it is not fully retained by the body. Approximately 50% of vitamin K is excreted through feces, and 20% through urine, highlighting the importance of a diet rich in leafy greens. These vegetables are not only high in vitamin K but also provide essential nutrients such as vitamins A, C, and E, iron, magnesium, potassium, calcium, carotenoids, antioxidants, and fiber.

What Is Vitamin D?

Vitamin D, or calciferol, is a fat-soluble vitamin found in certain foods, added to products like milk, and available as a dietary supplement. Known as the “sunshine vitamin” because the body can produce it when exposed to sunlight, vitamin D plays a crucial role in promoting calcium absorption in the bones and preventing excess calcium buildup in the blood. A deficiency in vitamin D can result in weak, brittle bones and lead to osteoporosis in adults, while in children, it helps prevent rickets.

There are two main forms of vitamin D: D2 and D3, with D3 being the most active form in the body. Vitamin D can be obtained from food sources such as salmon, trout, tuna, fish oils, mushrooms, and egg yolks. Additionally, certain foods are fortified with vitamin D, including milk, margarine, cheese, ice cream, and plant-based milk alternatives like soy, almond, or oat milk. Your body can also produce vitamin D through sunlight exposure, though factors such as the time of day, cloud cover, smog, and skin melanin content can affect how much sunlight is absorbed. While it’s crucial to protect yourself from excessive UV light to avoid serious skin conditions, it’s important to remember that sunscreen can reduce the UV light needed for vitamin D synthesis. This is why many foods are fortified with vitamin D and why supplementation is often recommended.

Cardiovascular Risk Factors

According to the World Health Organization (WHO), cardiovascular diseases are the leading cause of global mortality, with an estimated 17.9 million deaths attributed to these conditions in 2019. Cardiovascular diseases include coronary heart disease (which can lead to heart attacks), cerebrovascular disease (which can cause strokes), and peripheral arterial disease (which affects the blood vessels in the arms and legs). Heart attacks and strokes typically result from blocked blood flow to the heart or brain, often due to the accumulation of fatty deposits in the arterial walls. The positive news is that most cardiovascular diseases can be prevented through lifestyle changes and by addressing risk factors such as smoking, obesity, poor diet, physical inactivity, and excessive alcohol consumption.

One of the most effective ways to prevent cardiovascular disease is to adopt a healthy diet and quit tobacco use. Cutting down on processed foods high in salt, avoiding tobacco products, and limiting alcohol consumption can greatly reduce the risk of cardiovascular diseases. A diet rich in fruits and vegetables, along with engaging in at least 30 minutes of physical activity daily, are key practices that can help protect against cardiovascular conditions.

Synergistic Effects of Vitamins K and D

The Journal of Nutrition has emphasized the potential synergistic benefits of vitamins D and K for cardiovascular health. Low levels of these vitamins are linked to high blood pressure and increased arterial wall thickness. Vitamin D is known to enhance the production of vitamin K-dependent proteins. While it’s possible to supplement with vitamin D or vitamin K individually, combining both may offer more significant benefits.

A study by Dal Canto et al., which included 601 individuals aged 70 and older, found that those with low levels of both vitamin D and vitamin K had higher body mass indexes (BMIs), a greater prevalence of chronic conditions such as type 2 diabetes, and elevated blood pressure compared to those with normal vitamin levels. Additionally, individuals with low levels of these vitamins were more likely to use heart disease medications. Among the 601 participants, 321 with chronic conditions like high blood pressure showed structural changes in their heart muscles, and these individuals also had low levels of vitamins D and K.

In the VINDICATE study, which examined the effects of vitamin D on cardiac function in patients with chronic heart failure, high-dose vitamin D supplementation (around 4,000 International Units [IU]) was linked to improved cardiac function, reflecting enhanced heart pumping ability. Additionally, women (but not men) with higher levels of vitamin K experienced improvements in their left ventricular mass index, a measure of the heart’s size and workload related to high blood pressure.

Recommended Intakes of Vitamins D and K

In addition to eating leafy greens, many multivitamin supplements offer about 75% of the recommended daily value of vitamin K. Some dietary supplements provide vitamin K alone or combine it with other nutrients such as calcium, magnesium, or vitamin D. The recommended daily intake of vitamin K is 120 micrograms (mcg) for men and 90 mcg for women. Before starting vitamin K supplementation, it is wise to consult with a healthcare provider, as it may interact with certain medications, especially those used to prevent blood clotting.

To boost vitamin D intake, besides consuming fish, milk, or getting sunlight, you might consider taking vitamin D supplements, either alone or combined with calcium. Vitamin D is measured in both micrograms (mcg) and International Units (IU), where 1 mcg equals 40 IU. The recommended daily allowance for adults up to 70 years old is 600 IU (15 mcg), while those aged 70 and older should aim for 800 IU daily. Some professional organizations, like the Endocrine Society, suggest higher intakes, recommending that adults take 1,500–2,000 IU per day.

Key Takeaway

Safeguarding cardiovascular health is vital for a long and healthy life. According to the World Health Organization, many risk factors for cardiovascular disease are modifiable. Vitamins K and D also play a role in supporting heart health. However, it’s important to consult with a healthcare provider before starting any new supplements, especially if you’re on medications that might interact with them. A balanced diet rich in leafy greens and vegetables can help prevent serious cardiovascular issues, enabling you to lead a long, healthy, and fulfilling life.