The connection, if any, between vitamin D and cholesterol is unclear. Some research suggests that vitamin D supplements may improve cholesterol levels. However, others indicate that vitamin D has no effect on low-density lipoprotein (LDL) cholesterol.

Vitamin D is important for maintaining healthy bones and teeth, and the human body produces it when the skin has exposure to the sun. However, a person may also take vitamin D supplements.

The body also produces cholesterol. As this substance is in some foods, people may take in extra through their diet. Cholesterol plays several roles in the body, contributing to the production of vitamin D and several hormones.

Keep reading to learn about vitamin D, including its possible connection to cholesterol, its benefits, and the effects of a vitamin D deficiency.

Share on Pinterest
Granger Wootz/Getty Images

Studies investigating the effects of vitamin D on cholesterol have produced inconsistent results. For example:

  • A study of the short-term effects of taking vitamin D supplements reported that doing so increased levels of LDL, or “bad,” cholesterol.
  • Other research evaluated the effects of combined calcium and vitamin D (CaD) supplements on people who had been through menopause. It noted an improvement in all types of cholesterol, including LDL cholesterol.
  • According to the National Institutes of Health (NIH), research results are mixed, with an analysis of 41 clinical trials showing a reduction in the levels of LDL cholesterol. Vitamin D supplementation did not affect the levels of high-density lipoprotein (HDL), or “good,” cholesterol.

Vitamin D is a fat-soluble vitamin that the body needs to perform several functions, including the maintenance of strong muscles, teeth, and bones. The nerves, muscles, and immune system also use it.

In combination with calcium, vitamin D can help protect against osteoporosis.

The body produces the vitamin as a result of direct sunlight on the skin, and people can increase their levels by eating certain foods. Another option is to take vitamin D supplements, which may be particularly beneficial for people at higher risk of deficiency, including:

  • individuals who rarely go outside, always use sunscreen, or keep their head and body covered
  • older adults
  • those with obesity
  • people with darker skin, as the body may need longer exposure to sunshine to produce the vitamin
  • breastfed infants
  • individuals with certain conditions, such as celiac disease, ulcerative colitis, or Crohn’s disease
  • people who have had gastric bypass surgery

Food sources

The NIH state that the vitamin is naturally present in the following food sources, albeit in varying amounts:

  • oily fish, such as salmon, trout, mackerel, and tuna
  • fish liver oils
  • eggs
  • cheese
  • beef liver
  • mushrooms
  • meats, such as turkey, beef, and pork

In addition, some manufacturers fortify their foods with vitamin D. These fortified foods provide most of the vitamin D content in the diet of those living in the United States, according to the NIH. These sources include:

  • milk
  • many brands of milk alternatives, such as soy, oat, and almond milk
  • many brands of breakfast cereal
  • some brands of orange juice, yogurt, and margarine

Additional benefits

The benefits of vitamin D supplements for people with heart disease, multiple sclerosis, depression, cancer, type 2 diabetes, or excess body weight are either unclear or unsubstantiated, according to the NIH.

In addition, a review of studies on the effects of vitamin D on asthma indicates that larger trials are necessary to determine these.

People with low levels of vitamin D may experience symptoms as a result of the deficiency leading to complications.

Symptoms

People may experience symptoms of the following conditions, which can result from vitamin D deficiency:

  • Rickets: Vitamin D deficiency may cause children whose bones are still growing to develop rickets. This condition can result in bone softness, skeletal abnormalities, and pain.
  • Osteomalacia: In people of all ages, vitamin D deficiency can cause osteomalacia, with symptoms including bone weakness and pain, along with muscle weakness.
  • Dental problems: A review of several studies identified an association between a deficiency of vitamin D and a higher risk of oral health issues, including enamel defects, periodontitis, and caries.
  • Depression: Low vitamin D levels may link to depression, according to a review of 61 articles, although the authors concluded that there is insufficient evidence to recommend the use of vitamin D supplements.
  • Fatigue: There are many possible causes of fatigue, with a case study suggesting that vitamin D deficiency may be among them.

Risk factors

The NIH list the following causes of vitamin D deficiency:

  • poor absorption from the intestinal tract
  • the inability of the kidneys to convert the vitamin to its active form
  • low exposure to sunlight

Another cause is low intake of vitamin D in the diet. The NIH explain that this is more common in:

  • people with a milk allergy
  • individuals with lactose intolerance
  • people eating a vegan or ovo-vegetarian diet

Other possible risk factors for a vitamin D deficiency include smoking, pollution, medications, skin type, age, pregnancy, and geographic location.

High cholesterol levels may not cause symptoms, according to the National Heart, Lung, and Blood Institute (NHLBI), but they may lead to serious problems over time. The problems stem from the accumulation of plaque in the blood vessels.

The NHLBI state that high cholesterol levels may result in the following:

  • heart attack
  • stroke
  • chest pain
  • carotid artery disease, which is the buildup of plaque in the arteries in the neck that supply blood to the brain
  • peripheral artery disease, which is the buildup of plaque in the peripheral arteries and generally occurs in the legs and feet
  • coronary artery disease, a condition in which the coronary arteries cannot carry enough oxygen-rich blood to the heart
  • high blood pressure

If a person suspects that they have a vitamin D deficiency, they may wish to schedule a blood test that will measure the levels of this vitamin in their body.

Although vitamin D supplements are available without a prescription, hypercalcemia can result from excessive vitamin D intake (vitamin D toxicity). It is important to note that this condition is not a side effect of normal vitamin D intake.

In general, a person should check with their doctor before taking vitamin D supplements.

Research on the connection between vitamin D and cholesterol is inconclusive. However, because the body needs vitamin D for several functions, it is important to get regular exposure to sunlight, if possible.

People may be able to prevent vitamin D deficiency by including certain foods in their diet, including milk, cheese, oily fish, meat, eggs, and fortified foods.