Muscles

Muscles generate the force that creates speed during exercise. Muscles benefit from nutrients that complement their biochemistry. Here we will present some basic information about muscles and how vitamin K, vitamin D, and Astaxanthin help maximize muscle performance.

Tip: Muscles are part of a system and internal to each muscle fiber or group of muscle fibers is a sub-system

Vitamin K is a co-factor to activate important proteins in muscles, leading to better physical performance. Astaxanthin is an organic pigment, which gives certain marine animals their pink color, like salmon or plankton. Asta also reduces inflammation and muscle damage. Vitamin D3 is a both a nutrient we consume and a hormone we make from our exposure to sunlight. Vitamin D is important for muscle growth and development.

After puberty, men have about 36% more skeletal muscle mass than women. Women, at puberty and beyond, lose approximately 10 to 15% of their muscle mass, and put on less muscle mass over time, compared to males. People who are tall or overweight also tend to have higher muscle mass. Muscle mass decreases with age in both men and women, which leads to sarcopenia, which is a loss of muscle strength and mass.

Muscle fibers can be classified as type I, or type II fibers. Type I are referred to as slow twitch and type II are known as fast twitch. Type I fibers have the highest mitochondrial content which increases their endurance (Jacobs et al, 1985; Psilander, 2014). Exercise leads to the development of more mitochondria in muscle (Harper et al, 2021) so as to maintain the supply of ATP which facilitates movement.

Some believe that maximal oxygen uptake is dependent on the muscle fiber oxidative capacity (van der Zwaard et al, 2016; Wisloff et al, 1998). Muscle responds to its environment. If there is inactivity, muscle withers and atrophies (if you don’t use, it you lose it). With activity and exercise, muscle adapts.

Below we present research illustrating the benefits that vitamin K, vitamin D and astaxanthin have on your muscle health and function.

Endocrine Organ
Skeletal muscle is no longer seen as merely a machine for movement, but as an endocrine organ, and an immune reservoir. Skeletal muscles play a crucial role in whole-body metabolism, as muscle is a major storage site for glucose, lipids, and amino acids. During resting periods, skeletal muscles store energy, in the form of triglycerides and glycogen, which are then released as needed to meet the demand during exercise (Karsenty & Mera, 2018; Mera et al, 2018; Lavin et al, 2022).

Fat
Fat, in the form of triglycerides, is stored as lipid droplets inside muscle fibers (van Loon et al, 2001). During exercise, the triglycerides are broken down into glycerol and free fatty acids in a process called lipolysis (Ogasawara et al, 2015; Watt & Spriet, 2010; Zechner et al, 2009). The fatty acids are released to the circulation and directed into muscle cells, then transported to the mitochondria (i.e., energy factory of the cell) to be broken down to produce ATP as fuel (Thompson et al, 2012).

Individuals with higher fitness have a greater storage capacity and ability to metabolize intramuscular triglycerides (IMCL). Endurance-trained athletes rely more heavily on IMCL to fuel exercise. Fat is your friend.

More Endurance/Better Physical Performance
Type II or fast-twitch muscle fibers are extremely important in many of the burst activities necessary for peak athletic performance and fall avoidance (Bartoszewska et al, 2010). Type II, fast-twitch muscle fibers are particularly sensitive to the effects of vitamin D deficiency, where levels below 30 nmol/l are associated with decreased muscle strength (Bischoff et al, 1999; Pfeifer et al, 2002).

Eighteen healthy adult male distance runners from a local university took 6 mg/day of asta for four weeks. They ran 1,200 meters at the start of the study to establish a baseline, and at the end, when their lactic acid concentration was measured. Those who took the asta showed significantly lower levels of lactic acid concentration and muscle fatigue two minutes after running than those who had no asta, suggesting their aerobic metabolism in muscle had improved (Sawaki et al, 2002)

Early studies with mice showed that Astaxanthin significantly increased their ability to swim longer. They were given 1.2, 6, or 30 mg/kg of body weight over five weeks, Those given asta showed continuous, significant improvement in how long they could swim before exhaustion, and had significantly lower lactate levels, and decreased fat accumulation, compared to those who were not given astaxanthin (Ikeuchi et al, 2006). Another study looked at effect of asta on muscle lipid metabolism during exercise in mice. Those who were given asta for four weeks showed increased fat utilization in muscle which created more energy and which led to improved endurance (Aoi et al, 2008).

A study of 40 healthy males in Sweden at a paramedical school took 4 mg of Astaxanthin over a period of six months, while leading a normal life. Standardized exercise tests measuring fitness, strength/endurance, and strength/explosivity were carried out before the trial and after 3 and 6 months. Those who took Astaxanthin made a significant gain in strength/endurance and demonstrated a three times greater improvement than those who did not take Asta (Malmsten et al, 2008).

A similar gain was reported in 14 amateur trained male cyclists who cycled about 160 km per week and had a VO2Max greater than 50. They took asta for four weeks 4 mg/day and significantly improved their time trial by 5% (Earnest et al, 2011).

A study of 1089 elderly participants in the Health ABC study found that those with higher levels of vitamin K had better physical performance scores (Shea et al, 2016). The same research team looked at a 1300 men and women with a mean age of 74.6 years, 60% Caucasian and 40% black. At follow up, those with low vitamin K1 levels were more likely to develop mobility limitation and disability (Shea et al, 2020).

Cyclists were given Asta supplements for seven days (12 mg/day) or a placebo, separated by 14 days of washout. (Tip: washout means that the Asta is gone in 14 days). On the seventh day, they completed a 40 km time trial. Those who received Asta showed a 1.2 to 2.9% improvement, along with better whole-body fat oxidation and a lower respiratory exchange ratio (Brown et al, 2020).

Research has been able to show that osteocalcin signaling supports glucose and fatty acid utilization during exercise, meaning greater energy is produced (Lin et al, 2017; Tsuka et al, 2015; Pi et al, 2016; Moser & van der Eerden, 2019; Mera et al, 2016). Keep in mind that adequate amounts of vitamin K intake are necessary for osteocalcin to be part of this energy creating cycle.

A follow up study of the elderly, age 65-82, at the UW Medical Center were engaged in three months of training, while measuring specific muscle endurance and fat oxidation. Half the group were given Astaxanthin. The dietary formulation consisted of Astaxanthin (12 mg), tocotrienol (10 mg), and zinc (6 mg). (The suggested intake for tocotrienol is 250 mg/day). Only those who received the Astaxanthin showed improved muscle endurance and an increase in Fat oxidation, especially in older males (Liu et al, 2021).

Peak muscular performance is associated with blood levels of 25(Oh)D falling at or above 50 ng/mL (Shuler et al, 2012).

More Power and Strength
A study of adolescent Chinese students found that their vitamin D levels were associated with increased jump velocity, height, power, and force (Ward et al, 2009). In another study, Chinese adolescent girls were tested for their vitamin D levels and 57.8% were found to be deficient and 31.2% were severely deficient. Those with deficiency presented with significantly lower bone mass and muscle strength (Foo et al, 2009).

UK athletes were given 5000 ius/day (125 mcg) of vitamin D for 8 weeks, resulting in a significant increase in their 10 meter sprint times and vertical jumps (Close et al, 2013).

Active males engaged in 30 minutes of physical activity at least 3 times per week and were given 4000 ius (100 mcg) of vitamin D for 35 days. They showed an enhanced muscle strength recovery (Barker et al, 2013). In another study, men exercised and were given 4000 iu/day of D3 for six weeks (2- and 7-days post exercise) which resulted in a 14% improved strength recovery (Owens et al, 2015).

Elite ballet dancers were given 2000 ius/day (50 mcg) of vitamin D3 and showed an 18.7% increase in isometric strength and a 7.1% increase in vertical jump, while sustaining significantly few injuries (Wyon et al, 2014).

A vitamin K deficiency as reflected in measures of osteocalcin was associated with lower muscle strength in young women (Levinger et al, 2014).

Handgrip indicates muscle strength and is directly related to lower-extremity strength. Calf circumference indicates skeletal muscle mass and is associated with higher strength (Jakobsen et al, 2010; Rolland et al, 2003). A longitudinal cohort study conducted in community-dwelling adults analyzed the association between vitamin K status and physical functioning over 13 years. Low vitamin K status was associated with lower handgrip strength, smaller calf circumference, and poorer functional performance (Ballegooijena et al, 2018; Machado-Fraguo et al, 2010).

Muscle Mass
Sarcopenia is defined as the loss of muscle mass tissue and strength due to aging. An ongoing longitudinal study in Belgium of the independent elderly found that those who were diagnosed with sarcopenia consumed lower amounts of proteins and fats, and lower amounts of five micronutrients; potassium, magnesium, phosphorus, iron, and vitamin K (Beaudart et al, 2016).

A meta-analysis of research on athletes showed a prominent vitamin D inadequacy, with 56% of those in the review being low, which varied by geographical location, with the deficiency increasing for winter and spring seasons and indoor sport activities. The prevalence of injuries associated with low vitamin D levels was 43% bone related and 37.5% soft tissue related (Farrokhyar et al, 2017).

A formulation of astaxanthin, tocotrienol, and zinc, improved the muscle strength and tibialis anterior muscle size in healthy elderly working on an inclined treadmill 3 x a week for 4 months (Liu et al, 2018).

Observational studies conducted on patients with sarcopenia showed that high levels of vitamin K were associated with muscle strength, large muscle mass and high physical performance (Azuma & Inoue, 2019).

Vitamin K deficiency is correlated with progressive reductions in muscle mass. The authors concluded that vitamin K2 moderates skeletal muscle mitochondria, and recommended studies on vitamin K2 supplementation to prevent muscle mass loss (Rønning et al, 2018; Simes et al, 2019). A lab study showed that vitamin K2 increased slow twitch muscle fibers and improved mitochondrial function (Su et al, 2022). A study found that dietary vitamin K intake was associated with great muscle mass in men (Wang et al, 2024).

It has been demonstrated that carboxylated or activated osteocalcin correlates with muscle mass and risk of fall in postmenopausal women. Older women with low vitamin K intake, have less muscle mass and a moderate-severe risk of fall (Vitale et al, 2021). Uncarboxylated or inactive osteocalcin has been implicated in muscle hypertrophy and strength. Mice with OCN deletions have lower muscle mass (Lin et al, 2016), and the administration of ucOCN increased muscle mass in older mice (Mera et al, 2016). Osteocalcin is a protein that depends on vitamin K to be active and effective.

Anti-Inflammatory
Intensive and sustained physical activity can result in the increased production of reactive free radicals and reactive oxygen species (ROS) through the increase in oxygen consumption. Increased oxygen consumption leads to oxidative stress which may have a negative impact on cellular and immune function (Pingitore et al, 2015). Consequently, lipid, protein and nucleic molecules may become damaged, with potentially detrimental impacts on normal physiological function (Dalle-Donne et al, 2006).

Antioxidant vitamins can be an important intervention for inflammation, though it has been suggested that athletes under heavy training and competition are not able to maintain optimal tissue levels of antioxidant vitamins, even if the recommended daily allowances are consumed through their diets (Davies et al, 1982; Peternelj & Coombes, 2011).

Astaxanthin has gained attention due its strong antioxidant capacity as well as anti-inflammatory properties (Park et al, 2010; Kidd, 2011; Yoshihara et al, 2019). 12 weeks of 8 mg/day Astaxanthin supplementation was reported to reduce markers of free radical inflammation in healthy untrained males (Karppi et al, 2007).

A randomized, double-blind, placebo-controlled study was conducted to investigate the effects of Astaxanthin on lipid profiles and oxidative stress in overweight and obese adults in Korea. They were given either 5 mg or 20 mg once daily for three weeks. The stress markers were lowered, while the total antioxidant capacity was significantly increased in the two dose groups after only three weeks. It appeared that the Asta improved oxidative stress by suppressing lipid peroxidation and stimulating the antioxidant defense system (Choi et al, 2011).

Soccer players from the Partizan club in Belgrade, Serbia were recruited for a trial, using naturally derived Asta from Sweden. They were in good health, had no injuries and were not on medication and were non-smokers. They had 5 to 7 training sessions per week, totaling about 10 to 15 hours. They were given a placebo or Astaxanthin for 90 days, then engaged in an intense workout. The results indicated that soccer training and exercise were associated with oxidative stress, which might diminish antioxidant system efficiency and that Astaxanthin could prevent inflammation (Djordjevic et al, 2012). A follow up study of the male soccer players showed that those who received Asta had an improved immune response and less muscle damage from training. The researchers hypothesized that Asta protects the cell membranes against free radicals in muscle tissue, thus preserving their functionality (Baralic et al, 2015).

High sensitivity CRP (c-reactive protein) is a measure of inflammation. A British study showed that residents with a deficient level of vitamin D had a significantly elevated CRP score, indicating more inflammation. Irish residents with a low-deficient level of vitamin D showed higher levels of CRP (Laird et al, 2023; Zhou & Hypponen, 2023). (Tip: an additional measure of inflammation is IL-6, or TNF- alpha).

The adaptation of skeletal muscle function to strenuous exercise is partly attributable to vitamin D status. 24 runners of ultra-marathons were given 2000 IU of vitamin D or a placebo for three weeks. All the subjects participated in three exercise protocols and had blood tests of their D levels, muscle biomarkers, proinflammatory cytokines and tumor necrosis factor-alpha (TNF-α) levels. The runners who received vitamin D showed a marked decrease in post-exercise biomarkers, suggesting that vitamin D may prevent skeletal muscle injuries following exercise (Zebrowska, et al, 2022).

18 healthy subjects capable of running 2.25 hours on lab treadmills at 70% VO2Max took 8 mg/day of Astaxanthin. The running induced significant muscle soreness, damage and inflammation. The Asta inhibited exercise-induced decreases in 82 plasma proteins that are involved in immune-related functions. IgM immunoglobulins are produced by plasma cells as part of the body's adaptive humoral immune response against a foreign pathogen and the plasma levels of IgM was significantly reduced after exercise but recovered within 24 hours in the group that received Asta. Those who received the placebo did not show the same quick recovery (Nieman et al 2023).

Muscle Health
In a study of ambulatory people over 60 years of age, vitamin D concentrations between 40 and 94 nmol/L were associated with better musculoskeletal function in the lower extremities. Lower-extremity function improved continuously with higher 24(OH)D concentrations through the reference range, with the most improvement occurring in the concentrations between the lowest values and 40 nmol/L (Bischoff-Ferrari et al, 2004).

A study of NFL athletes found that 81% had vitamin D levels that were at or below deficient and those with lower levels had more muscle injuries (Shindle et al, 2011).

Leg Cramps
Leg cramps are characterized by involuntary, painful, sudden contractions of the skeletal muscles, accompanied by pain or muscle hardening, and are typically found in the lower extremities such as the calf muscle. A study showed that using MK7 for three months relieved muscle cramps (Mehta et al, 2010). Another trial of people over 65 showed that taking MK7 for 8 weeks significantly reduced the frequency, intensity and duration of leg cramps at night (Tan et al, 2024). A clinical trial showed that vitamin K2 reduced the frequency and severity of muscle cramps in patients on dialysis within eight weeks, with a further reduction in the next eight weeks. The group receiving the placebo had no significant reduction in the frequency of cramps. Furthermore, the improvements went away when vitamin K2 was replaced with the placebo (Xu et al, 2022).

Tip: Keep your Magnesium levels up and avoid Phosphoric Acid containing drinks. Phosphoric Acid binds Magnesium and removes it from your body. Cola drinks and some flavored waters contain Phosphoric Acid. Clear carbonated drinks such as ginger ale, lemon-lime sodas, and flavored seltzers are less likely to contain Phosphoric Acid.

Role of Osteocalcin
Osteocalcin is a protein that depends on vitamin K to be active. Osteocalcin impacts exercise through its role in glucose metabolism and its role in inducing the expression of interleukin 6 (IL-6), a myokine that increases exercise capacity (Komori, 2020).

A low undercarboxylated OCN/OCN ratio was associated with lower muscle strength in young women (Levinger et al, 2014).

It has been demonstrated that carboxylated osteocalcin correlates with muscle mass and risk of fall in postmenopausal women. This suggests that older women, with low intake of vitamin K, have less muscle mass and thus a moderate-severe risk of fall (Vitale et al, 2021).

Uncarboxylated or inactive osteocalcin has been implicated in muscle hypertrophy and strength. Mice with OCN deletions have lower muscle mass (Lin et al, 2016)], and the administration of ucOCN increased muscle mass in older mice (Mera et al, 2016).

Osteocalcin, age, and performance
Osteocalcin naturally declines in humans as we age, beginning in women at age 30 and in men at age 50. This decrease in circulating bioactive OCN occurs at the same time as the ability to perform exercise declines (Merat et al, 2016a). However, during exercise in both mice and humans, the levels of osteocalcin in the blood do increase, depending on age (Levinger et al, 2014; Rahimi et al, 2020; Rahimi et al, 2021).

To investigate whether osteocalcin levels were affecting exercise performance, Karsenty and his colleagues tested mice genetically engineered so osteocalcin could not signal properly in their muscles. Without osteocalcin muscle signaling, the mice ran 20%-30% less time and distance than their healthy counterpart. It was concluded that the osteocalcin signaling in muscle favors adaptation to exercise because it promotes the uptake of glucose and fatty acids, a necessary step to create energy (Mera et al, 2016a; Karsenty & Olsen, 2016; Diaz-Francos et al, 2019).

A study of Japanese community dwelling older adults found that low levels of osteocalcin, reflecting K intake, was associated with frailty, slow walking speed, and low activity (Azuma et al, 2022).

OCN supports muscle function during exercise through an additional mechanism: it favors the expression and release of interleukin 6 (IL-6), the first molecule found to be secreted into blood in response to muscle contraction (Steensberg et al, 2000; Pedersen & Febbraio, 2008). Interleukin 6 is believed to increase exercise capacity by enhancing glucose production in the liver, lipolysis in white fat tissue, and glucose uptake by myofibers (Pedersen & Febbraio, 2012; Pal et al, 2014; Lin et al, 2017). Research with mice revealed that muscle-derived IL-6 is necessary for optimum ability to exercise (Chowdhury et al, 2020).

In summary, the research shows that the nutrients of vitamin K, D, and Astaxanthin each contribute support and enhancement to muscles and athletic performance. They enhance muscle strength, muscle mass, support greater strength and power, higher performance levels, and are anti-inflammatory which helps with recovery. Osteocalcin, which is activated by vitamin K, significantly restored exercise capacity. These three nutrients are available in Ultra K.

Tip: These three nutrients are available in Ultra K.

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