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While it may not be surprising that more men than women die of cardiovascular complications, the fact that low bone mineral density is a rising problem in males may be news to many men, as well as their doctors.

The National Institutes of Health online reports, “In the past few years the problem of osteoporosis in men has been recognized as an important public health issue, particularly in light of estimates that the number of men above the age of 70 will continue to increase as life expectancy continues to rise.” 9

It’s hard to believe that both hardened arteries and low bone mineral density are related to Calcium; however, it isn’t the lack of calcium intake, but rather, it’s the lack of absorption that’s the actual root of the problem.*

To illustrate this more clearly, here are some well-researched facts and statistics:

  • “Up to 90 percent of peak bone mass is acquired by age 18 in girls and by age 20 in boys, which makes youth the best time to ‘invest’ in one’s bone health.” 10
  • “In the first few years after menopause, most women go through rapid bone loss, a ‘withdrawal’ from the bone bank account, which then slows but continues throughout the postmenopausal years. This loss of bone mass can lead to osteoporosis.” 10
  • “Controllable lifestyle factors such as diet and physical activity are responsible for 10–50 percent of bone mass and structure.” 15
  • “Vitamin D promotes calcium absorption gut and maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and to prevent hypocalcemic tetany.” 7
  • “If you don’t eat a nutritious variety of foods, some supplements might help you get adequate amounts of essential nutrients.” 4

Because of the lack of nutrients in conventionally grown crops and factory farm animals, the average American diet typically does not provide all the vitamins a healthy person needs. In addition, new research about the importance of vitamin K, vitamin deficiency, and the combination of A, D, and K (specifically, K2) begs further examination of how certain vitamins work together to help the absorption of vital nutrients.*


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Calcium Bone Health

The formula in A • D • K from DaVinci® Laboratories is based on scientific research examining the synergistic effects of vitamins A, D3, and K2.

In her well-researched and documented book, Vitamin K2 and the Calcium Paradox, Kate RheaumeBleue, ND argues that the combination of vitamins A, D and K are, “intricately interrelated in complex ways that modern science doesn’t yet entirely understand.” 12

Dr. Rheaume-Bleue points out that the, “bone-building benefits of vitamin D,” depend on vitamin K2, and when vitamin D is, “assisted by vitamin A,” this relationship, “stimulates the production of osteocalcin,” which is activated by vitamin K2. She contends that these fat-soluble vitamins are, “profoundly different,” than other nutrients because they bind to proteins, especially K2, which allows the proteins to bind to calcium so that it can be better utilized in the body.* 12

The Synergistic Effect of Vitamins A, D, and K

Vitamin A is a fat-soluble vitamin with multiple functions in the body, including normal development, growth and maintenance of the skeleton throughout life. Vitamin A supports the number and activity of osteoclast cells, which break down bone tissue, an ongoing process of skeletal maintenance called bone remodeling.* 12

Vitamin D3 (Cholecalciferol) is a fat-soluble vitamin that is essential for maintaining normal calcium metabolism.* It supports calcium absorption in the gut and helps maintain adequate serum calcium and phosphate concentrations to enable normal mineralization of bone. Vitamin D3 also supports cardiovascular function and blood pressure within normal ranges.* 12

Vitamin K2, known as menaquinone (MK- 7), is the form that has been shown to support normal bone formation.* It is responsible for the carboxylation of specific bone proteins that play a regulatory role in bone metabolism.* Factors that cause a vitamin K deficiency include: poor diet and the use of certain prescription drugs, as well as long term use of antibiotics.* 12

Vitamin K1 vs. K2 In Chapter 3 of Dr. Rheaume-Bleue’s book, she takes an in depth look at how much vitamin K2 is needed and where to get it. She also makes the distinction between vitamin K1 and K2. Vitamin K1 (found in nutrient rich greens) is the precursor to K2, which is the form that supports calcium utilization. While humans cannot convert vitamin K1 into K2, animals can, which is why meat and dairy products are another source of K2.12

According to the National Institutes of Health, only a third of the United States population meets the Adequate Intake of vitamin K.This may be due to the development of large beef and poultry feedlots and factory farming practices. Most modern factory farms use corn because it is cheap and fattens the animal more quickly. However, this means that grain-fed animals are not as healthy, and the meat is higher in saturated fats. It also means that the animal product doesn’t provide a good source of K2. According to Dr. RheaumeBleue’s research in her book, standard grain, “contains only a fraction of the necessary K2 precursor found in green grass.” 12

She concludes that before the rise of commercial feedlots, vitamin K2 was abundant in our diets because most animals grazed on pastures. If factory farming and grain-fed animal products are the norm, how do we ensure that we are getting enough K2? Supplements are only part of the answer. Knowing where our food comes from is another large piece of the puzzle.


As a strange twist of fate, the discovery of vitamins A and D sparked the enormous shift in how livestock animals are raised in the U.S., starting as early as the 1920s. Dr. Rheaume-Bleue explains, “Adding these specific nutrients to feed meant that cattle, poultry and swine could survive without sunlight, a source of vitamin D, and without green grass, a source of nutrients from which animals can derive vitamin A.” 12

Buying quality animal products is one way to get a number of essential vitamins and minerals, not just K2. Without perhaps understanding the full extent of the health benefits of eating meat from grass-fed animals, “Localvore” movements across the country are leading the way to better health by promoting locally-grown, free range, and grass-fed beef, chicken, and pork. But some of these labels can be confusing.

Grain-fed vs. Grass-fed

It may seem like a luxury to some, but part of getting the right amount of minerals and vitamins includes making healthier food choices. This means we need to increase our awareness of where our meat comes from and how the animals are raised. A little education goes a long way.

For instance, many consumers don’t realize that “free range” is not the same as “grass-fed.” Buying cage-free eggs doesn’t mean that the hen has been fed the nutrient-rich grass needed to produce eggs with a higher nutrient content, which includes higher levels of vitamin A, E, D, K2, and Omega-3 fatty acids. It only means that the hen was not raised in a cage but may still have been fed mostly grain.

Why should any of this matter outside of environmental or ethical concerns? Dr. Rheaume-Bleue compares the official nutrient data for commercial eggs with the eggs from grass-fed hens. The results are staggering.

Hens raised on pasture have:

  • 1/3 less cholesterol
  • 1/4 less saturated fat
  • 2/3 more vitamin A
  • 2x more Omega-3 Fatty Acids
  • 3x more vitamin E
  • 7x more beta-carotene
  • 50% more Folic Acid
  • 70% more vitamin B12
  • 4-6x more vitamin D 12
  • 1/3 less cholesterol
  • 1/4 less saturated fat
  • 2/3 more vitamin A
  • 2x more Omega-3 Fatty Acids
  • 3x more vitamin E
  • 7x more beta-carotene
  • 50% more Folic Acid
  • 70% more vitamin B12
  • 4-6x more vitamin D 12
Even though some people argue that buying meat, eggs, or dairy from animals that were raised on pastureland is too expensive, they cannot argue with the nutritional deficit in most commercial products. In addition, it is widely accepted— even outside of “foodie” circles—that the taste and quality of grass-fed products are superior to that of standard grade.

However, with all the confusing labels surrounding the free range and organic movements, it’s hard to tell just how much vitamin K2 we are getting in our diets. In addition, the movement toward free range and grass fed is a slow one, and most consumers cannot afford these expensive items. Additionally, vegans are another subset of the population who can only get K2 through a supplement. Even if the majority of people who consume animal products are buying more nutrient rich meat and dairy, is it enough?


Benefits Of Vitamins A, D, And K

What makes A.D.K so beneficial is how its ingredients work together to help you achieve optimal health. Research indicates that the unique combination of vitamins A, D and K promotes proper bone growth and heart health.*

Vitamin A

Vitamin A is critical for bone growth as it helps stimulate bone building cells called osteoblasts. But, excessive amounts of Vitamin A have been linked to bone loss and an increased risk of fractures. Vitamin K2 supports the deposition of calcium into bone and acts as a regulatory role for Vitamin A.*

Vitamin D3- Cholecalciferol

Vitamin D3 is needed for proper bone growth and remodeling, a natural process that replaces weakened bone tissue with stronger tissue. A lack of Vitamin D3 may result in thin, brittle or misshapen bones. Vitamin K2 joins forces with D3 to help improve bone density and inhibit the production of cells that break down bone.*

Vitamin K - MK-7

Vitamin K2 is an essential nutrient that activates the heath-building benefits of vitamins A and D3. Vitamin K2 helps optimize calcium usage, prevent calcification of the arteries and maintain healthy blood pressure levels.*

Healthier Lifestyles Support Stronger Bones

While getting the extra support for certain health needs can be found in natural supplements,

it’s important to speak with patients about how a balanced diet and exercise are also a vital part of their overall health. This is why it is essential for health practitioners to recommend a comprehensive course of action for total wellness.

The Center for Disease Control notes that, “Recommendations from health care providers are the most influential factor in convincing people to be physically active,” as well as joining programs focused on self-management.2 This is why at DaVinci® Laboratories, we always encourage doctors to discuss the benefits of a healthy diet and exercise, along with the benefits of additional support from natural supplements.

The Difference Your Patients Are Seeking

There is a growing movement toward natural, alternative and non-prescription solutions for everyday health.

The 2007 National Health Interview Survey (NHIS) found that in 2007, around 4 in every 10 adults (38.3%) had used some type of complementary and alternative medicine (CAM). The NHIS also confirms that 38.1 million adults in the United States made visits to CAM practitioners during the last year, spending $33.9 billion out of pocket on visits and purchases of CAM products, classes, and materials.14 Calcium is among one of those out of pocket purchases, and more and more doctors are recommending calcium supplements for patients as they age. However, as Dr. Rheaume-Bleue argues, doctors are doing patients a disservice if that calcium is not being absorbed properly.

Calcium Supplements And Absorption

Calcium supplements are perhaps the most confusing since there are conflicting opinions about how much calcium is needed on a daily basis to support bone integrity. But what cannot be argued is how calcium is absorbed. The American Academy of Orthopaedic Surgeons states, “Not all the calcium consumed — whether through food or supplement — is actually absorbed in the intestines.” 1

AAOS also points to research suggesting that when calcium is taken in doses less than 500 mg, it is absorbed most efficiently. Therefore, splitting a high dose into multiple doses throughout the day would allow for greater absorption of calcium. 1 In addition to dosage, absorption is determined by the presence of other vitamins. Some research shows that when vitamins A, D, and K are combined, calcium is utilized more efficiently in the body. The AAOS encourages patients to speak with a doctor or specialist before taking a calcium supplement. While the combination of ADK has not been recommended for supporting bone and cardiovascular health, doctors who are recommending calcium supplements may want to consider the new research on calcium absorption and ADK supplements.

Bone Density and Rebuilding

Research shows that the combination of vitamins A, D, and K2 may support bone integrity and rebuilding. Vitamin K2 is required for the activation of osteocalcin—a vitamin K dependent protein that transports calcium from the blood to form a healthy bone matrix.*

Vitamin K2 has been tested in several clinical trials to examine its effect on bone mineral density, which reduces the risk of fracture.* In one study titled, ‘Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials,’ researchers found that adult participants taking oral vitamin K for at least 6 months saw a reduction in bone loss as well as a reduction in bone fractures. 3 However, a similar study was conducted using vitamin K1, finding no increase in bone mineral density. 11 This implies that vitamin K2 may have a more positive effect on bone mineral density than vitamin K1.*

As mentioned previously in this paper, vitamin K2 can only be found in animal meat or vitamin supplements. But it’s important to note that when vitamin K2 is lacking or not utilized properly in the body, bone structure and function can be compromised. Vitamin K2 not only supports the deposition of calcium into bone; it also has a regulatory effect on vitamins A and D with regard to osteoclast and osteoblast activity.* 12

This is partly why vitamins A and D are now being used with vitamin K in bone health supplements. Furthermore, some studies indicate that consuming high levels of vitamin A per day may cause reduced bone mineral density and increased risk of fracture. Therefore, experts recommend taking vitamins A in conjunction with vitamin K for its regulatory properties.

Vitamin D3 is also needed for proper bone growth and bone remodeling by osteoblasts and osteoclasts. Without sufficient Vitamin D, bones can become thin, brittle, or misshapen. Research shows that K2 partners with Vitamin D3 to inhibit the production of osteoclast cells (cells that break down bone) in order to help bone-building osteoblasts catch up to maintain a healthy balance.* 12

Bone remodeling is a natural way the body removes old or weakened bone tissue in order to make room for new, stronger tissue. This process is critical to fracture repair and retaining bone density. Vitamin A also plays a role in stimulating osteoblasts (bone building cells) to secrete proteins that are required for bone mineralization, including the K2 dependent protein called osteocalcin. Combined, vitamins A and D support osteocalcin output and the regulation of osteoclasts (bone breakdown cells) and osteoblasts (bone building cells).* 12

Vitamin K2 And Heart Health

In terms of heart health, vitamin K2 plays an important role, especially in reducing the risk of unabsorbed calcium collecting in coronary arteries. While both vitamin K1 and vitamin K2 have been found to be absorbed well in the body, one study indicated that MK-7 (vitamin K2) has a longer half-life and is therefore utilized for a longer duration.13 Furthermore, another study found that postmenopausal women receiving a steady dose of MK-7 over 3 years saw improved bone strength and reduced risk of vertebral height loss in the lower thoracic region. 5

Vitamin K2 works primarily outside of the liver in bones and blood vessels. In blood vessels, vitamin K2 helps to maintain arterial elasticity. Vitamin D3 also supports cardiovascular function and blood pressure within normal ranges. It impacts heart health by supporting the body’s natural cytokine production and vascular function.* 12

In her book, Dr. Rheaume-Bleue explains this synergistic relationship in one, simple statement: “Vitamins A and D collaborate to prop up vitamin K2, and we fully benefit from vitamins A and D only when we have K2 to complete the act and achieve optimal health.” She also points out another distinguishing trait shared by both vitamin A and vitamin D. Like vitamin K2, they can only be obtained from animal products, despite what health experts have been telling consumers for years. * 12



Our combination of A, D3, and K2 helps support: Bone structure, density and integrity, Proper bone remodeling,Calcium utilization, Cardiovascular function. Each capsule contains 5,000 IU of Vitamin A (as Retinyl Palmitate), 5,000 IU of Vitamin D3 (as Cholecalciferol), and 500 mcg of Vitamin K2 (as MK-7).