Home » Dietary Supplements » Vitamins

Vitamin D Deficiency Can Cause Muscle Weakness

  • Vitamin D is a fat soluble vitamin that you can get from vitamin D supplements, food or UV rays from the sun. But it’s better to take a dietary supplement than increase your risk of skin cancer
  • Vitamin D is necessary for calcium synthesis and is connected with bone health. It’s also essential in serving the body’s function and works in reducing inflammation
  • It’s important to use dietary supplements if you suffer from lactose intolerance since milk and other dairy products are a key source of dietary vitamin D


Vitamin D is a fat-soluble vitamin, and unlike most other vitamins, you can get it not only from food or supplements, but from the ultra violet rays of the sun. However you get your Vitamin D, whether through food or sunlight, it is inactive until your liver and kidneys complete a two stage process to make ‘active’ Vitamin D.

Vitamin D is necessary for Calcium synthesis, so it is closely connected with bone health. Without enough Vitamin D, the body cannot synthesize enough Calcium, and bones can become brittle or damaged. This is the cause of Vitamin D deficiency diseases like rickets (seen in children) and osteomalacia (in adults).

Vitamin D is also an essential part of immune function, and it aids healing of injuries by reducing inflammation. Vitamin D deficiency can cause muscle weakness and pain. Vitamin D has also been associated with cancer-prevention, especially colon cancer.

There aren’t many natural sources of Vitamin D from food, but these few sources are rich in Vitamin D. Milk and eggs are the most available sources, but oily fish, fish oils, and beef liver are other good ways to get your Vitamin D. Most of the milk available in the US today is fortified with additional Vitamin D.

Active people who spend a reasonable amount of time outdoors will probably meet their Vitamin D requirements from sun exposure alone during the summer months, although Vitamin D cannot travel with sun beams through glass or heavy cloud cover – or even sunscreens! Research has shown that people who live north of San Francisco or Boston should look to dietary source of Vitamin D during the winter. That means, if you are staying safe in the sun by avoiding midday rays in the summer, or covering up with clothing or sunscreen, you are limiting your Vitamin D intake. But it’s better to take a dietary supplement than increase your risk of skin cancer, so cover up!

Supplementation is important for people who are lactose intolerant, as milk and other dairy products are a key source of dietary Vitamin D. The recommended intake for adults is 5mcg or 200 IU per day, but that doubles for people over 50. Children and older people need to make sure their diet contains enough dairy products or fish oils to meet their additional needs, or they should consider supplementation. People on corticosteroid medications and some cholesterol lowering drugs may need Vitamin D supplements, because these medications can decrease the body’s ability to absorb Vitamin D.

Vitamin D supplements are usually in two forms D3 and D2. Vitamin D3 is known to be up to three times more effective as a supplement than D2, so look for this if you are choosing a supplement with Vitamin D.

It is difficult to get too much Vitamin D, but long term high dosages, especially with high levels of calcium supplements, may lead to kidney stones because of an increased blood level of calcium. Short term high dosages do not cause any ill effects, but over long periods toxicity can occur. In any case, doses of up to 50mcg or 2000IU per day are safe.

The information supplied in this article is not to be considered as medical advice and is for educational purposes only.

2 Responses to “Vitamin D Deficiency Can Cause Muscle Weakness”

  1. 1
    Muscler Says:
    I'm likely deficient in vitamin D because I don't see the sun much. Thanks for the info.
  2. 2
    Grace Says:
    People really need to make sure they take their vitamin D in the winter too. We tend to hibernate then and the sun is so weak we just don't get enough of the vitamins we need.