How much vitamin D for muscle growth?

Athletes of bodybuilding deficient in vitamin D could benefit from a vitamin D dose of 2,000-4,000 IU from supplements. Vitamin D may help build muscle mass, increase strength, and endurance.

Is vitamin D beneficial for muscle growth?

High serum vitamin D levels seem to be beneficial for muscle growth. Vitamin D is necessary for normal growth of muscle fibers and for proper muscle metabolism.[1,2]

Athletes of bodybuilding should be very cautious with their serum vitamin D levels, as vitamin D is highly associated with type II muscle fiber growth. Also, known as fast-twitch fibers. However, vitamin D deficiency may lead to atrophy of type II muscle fibers.[3]

There are two types of muscle fibers. The slow-twitch (or type I) and fast-twitch (or type II). Long-distance sports, such as running or cycling, mainly demand slow-twitch fibers. On the other hand, fast-twitch fibers are necessary for sports with quick powerful movements, such as weightlifting, bodybuilding, or sprinting.

Furthermore, vitamin D is important for the proper musculoskeletal function and physical performance.[4]

Vitamin D deficiency can seriously affect muscle strength and even lead to muscle weakness or pain.

Therefore, athletes of bodybuilding, or any other athlete that muscle hypertrophy is important, should regularly check serum vitamin D levels.

But, athletes with high serum vitamin D levels won’t build muscle mass by taking high dosages of vitamin D from supplements.[5]

Vitamin D deficiency is bad for athletes

Although most athletes follow a healthy, well-balanced diet, vitamin D deficiency is pretty common in athletes of all sports. In bodybuilding athletes as well.

Vitamin D deficiency is one of the most common nutrient deficiencies, as there aren’t many common foods high in vitamin D.[6]

Even many elite competitive athletes are deficient in vitamin D. Vitamin D deficiency may increase the risk of:[7]

  • stress fractures
  • structural pathology of muscle tissue
  • injury
  • inflammation
  • illness
  • gaining weight
  • delayed muscle recovery
  • bad sport performance
  • muscle cramps

Moreover, corticosteroid medications which are often prescribed to reduce inflammation can impair vitamin D metabolism. As inflammations are common in athletes, frequent medication may cause vitamin D deficiency. According to a study, people who take steroid medication have twice the risk of vitamin D deficiency.[1]

Bromelain in pineapple has anti-inflammatory properties and can relieve joint pain.

Vitamin D for better athletic performance

Vitamin D can affect muscle performance. Normal serum vitamin D levels have been linked to increased jump height, velocity and power. According to studies, vitamin D supplementation helped:[4]

  • professional soccer players increase their vertical jump and improve their sprint times.
  • ballet dancers increase their vertical jump by 7% and isometric strength by 18%.
  • judo athletes increase their muscle strength by 13%.

Zinc and vitamin C are also key compounds for muscle growth and improved endurance.

Can vitamin D decrease the risk of injury?

Low levels of vitamin D have been linked to muscle weakness after injury.

According to studies, ballet dancers and swimmers who took vitamin D supplements had decreased risk of injuries.[4]

In fact, injury incidences are lower in the summer, as people get high amounts of vitamin D from sun exposure.

Moreover, vitamin D seems to protect athletes from missing workouts or competitions. Especially elite athletes of endurance sports can benefit the most, as their immune system is suppressed and the body is pretty vulnerable to infections.

Athletes with optimal vitamin D levels have a lower risk of:[8]

  • upper respiratory tract infections
  • fewer days experiencing illness
  • fatigue
  • fracture
  • muscle injuries

What’s the best vitamin D dosage for athletes of bodybuilding?

The recommended daily intake of vitamin D for healthy adults is 600 IU. But, athletes of bodybuilding may require much higher dosages if they have low serum levels.

If serum vitamin D levels are less than 50 nmol/L (or 20 ng/mL), athletes could benefit from taking high doses of vitamin D from supplements. It’s vital to have vitamin D in normal rages for muscle growth.

In cases of acute vitamin D deficiency, even high vitamin D dosages of 10,000 IU can be beneficial for muscle growth and good health.

However, you should take more vitamin D than the maximum safe dose for healthy people only after consulting your healthcare provider. In most cases of vitamin D deficiency, a daily dose of 2,000-4,000 IU for a couple of months is enough to help athletes build muscle mass.

After all, most vitamin D supplements contain between 2,000 and 5,000 IU of vitamin D per tablet. You can compare prices between a wide variety of vitamin D supplements on iHerb.