What Happens to Your Body When You Take Vitamin D Regularly

What Happens to Your Body When You Take Vitamin D Regularly

Key Takeaways

  • Vitamin D is involved in many bodily functions and plays a vital role in immune health and maintaining healthy bones and teeth.
  • Vitamin D is produced when you expose your skin to sunlight and it is found in some foods, such as fatty fish and fortified dairy products.
  • The potential benefits of vitamin D supplementation are greater in people with a confirmed vitamin D deficiency.

Vitamin D is essential for immune system function and bone health, and may influence mood regulation and reduce the risk of several chronic health conditions. The body produces vitamin D when exposed to sunlight, but it may also be acquired through food and supplements.

1. You Maintain Healthy Bones and Teeth

Vitamin D helps the body retain and absorb calcium and phosphorus, which are important for building and maintaining healthy bones and teeth. Vitamin D deficiency may lead to decreased bone density, which can cause osteoporosis and broken bones.

2. Your Nerve Function Is Supported

Nerves need vitamin D so messages can be carried between the brain and other parts of the body. It is also needed for brain and nervous system development in the fetus.

3. Your Immune Health Can Function Optimally

The body’s immune system needs vitamin D to fight off disease-causing bacteria and viruses.

4. Your Moods May Be Better Regulated

Studies have shown that vitamin D may affect a person’s mental health by reducing negative emotions. Researchers have found that individuals with major depressive disorder and vitamin D deficiency are most likely to benefit from supplementation.

5. You May Reduce Your Risk of Some Chronic Disease

While more research is needed, several studies link vitamin D deficiency to several health conditions, including diabetes, some types of cancer, hypertension (high blood pressure), and multiple sclerosis.

6. You May See Better Weight Management

Some studies have found a link between obesity and low levels of vitamin D. However, more research is needed to clarify what role the nutrient plays in weight.

Does Vitamin D Give You Energy?

Vitamin D deficiency can cause tiredness. Studies have shown that vitamin D supplementation may improve fatigue in otherwise healthy individuals with a vitamin D deficiency.

How Do You Get Enough Vitamin D?

Vitamin D is a fat-soluble vitamin that has two primary forms: vitamin D2 (ergocalciferol), found in plants, and vitamin D3 (cholecalciferol), found in animal tissues.

Your body makes vitamin D when it’s exposed directly to sunlight. Most people get less vitamin D during the winter months because of insufficient exposure to sunlight. However, prolonged sun exposure is advised against because it can increase your risk of other ailments, such as premature aging and skin cancer.

This makes it necessary to get vitamin D from other sources. Dietary sources of vitamin D include:

  • Fatty fish, such as tuna, salmon, and mackerel
  • Mushrooms
  • Egg yolks
  • Beef liver
  • Cheese
  • Fortified dairy products
  • Fortified breakfast cereals and orange juice

What Are the Signs of Low Vitamin D?

Vitamin D deficiency is relatively common in the United States and many people with it have no symptoms. However, signs of low vitamin D may include the following:

  • Muscle pain
  • Muscle weakness
  • Dental problems
  • Fatigue
  • Bone pain
  • Depression
  • Cognitive impairment

Who Is at Risk of Vitamin D Deficiency?

Someone may have a greater risk of developing vitamin D deficiency if they take medications that interfere with vitamin D metabolism or if they have the following conditions:

  • A history of gastric bypass surgery (a type of weight-loss surgery)
  • Celiac disease (an immune reaction to the protein gluten found in wheat, barley, and rye)
  • Osteoporosis (reduced bone mineral density causing weak and brittle bones)
  • Chronic kidney or liver disease
  • Crohn’s disease (an inflammatory bowel disease causing chronic inflammation of the digestive tract)
  • Sarcoidosis (an autoimmune disease that causes collections of inflammatory tissue in parts of the body)
  • Histoplasmosis (an infection caused by breathing in fungal spores)
  • Tuberculosis (an infectious lung disease mainly caused by a bacterium)
  • Hyperparathyroidism (a condition where the parathyroid glands release too much hormone, raising calcium levels)

How Much Vitamin D Do You Need?

Vitamin D intake is measured in international units (IU) and micrograms (mcg). The amount of the nutrient you need depends on your age and other health factors.

The daily vitamin D requirements are as follows:

Life Stage Daily Recommended Amount
Birth to 12 months 400 IU (10 mcg)
Children 1–18 years old 600 IU (15 mcg)
Adults age 19–70 600 IU (15 mcg)
Adults over age 70 800 IU (20 mcg)
Pregnant and breastfeeding people 600 IU (15 mcg)

Do You Need a Supplement?

Your healthcare provider can order a blood test to measure the level of vitamin D in your blood. If your levels are low, your provider will likely recommend you take a vitamin D supplement to correct the deficiency.

When selecting a vitamin D supplement, you may want to choose D3 over D2. Both are easily absorbed by the body, but research suggests that vitamin D3 increases blood levels of the nutrient more and keeps those levels elevated longer than vitamin D2.

You should take a vitamin D supplement as directed by your healthcare provider, likely every day or week, based on the formulation.

Because vitamin D is a fat-soluble vitamin, it is best taken with meals or snacks containing fat, so the body can better absorb the nutrient.

Can You Get Too Much Vitamin D?

Vitamin D toxicity is unlikely to occur from diet or excess sun exposure since your body can control the amount of vitamin D it makes from the sun. In most cases, toxicity occurs due to the overuse of vitamin D supplements.

The main side effect of vitamin D toxicity is a condition called hypercalcemia, in which too much calcium builds up in the blood, causing symptoms like:

  • Nausea, vomiting
  • Confusion
  • Muscle weakness
  • Decreased appetite
  • Generalized pain
  • Excessive thirst and urination
  • Dehydration
  • Kidney stones

Extremely high vitamin D levels can cause more serious side effects, including irregular heartbeat, kidney failure, and death.

What Medications Interact With Vitamin D?

Some medications may interact with vitamin D supplements, decreasing their effectiveness or causing side effects. If you take any medications, check with your healthcare provider before taking a vitamin D supplement.

Drugs that vitamin D supplements interact with include:

  • Orlistat (Xenical, Alli): These weight-loss drugs may reduce the absorption of vitamin D.
  • Statins: High-dose vitamin D supplements may decrease the effectiveness of cholesterol-lowering drugs like atorvastatin (Lipitor), lovastatin, and simvastatin (FloLipid and Zocor).
  • Corticosteroids: Drugs like prednisone may decrease levels of vitamin D in the blood.
  • Diuretics: When taken with a vitamin D supplement, thiazide diuretics (like Thalitone, Lozol, and Microzide) can cause dangerously high levels of calcium in the blood.

People with hyperparathyroidism, kidney disease, or hypercalcemia (high blood calcium) should also speak with their healthcare provider before taking a vitamin D supplement.

Supplement Safety

In the United States, the Food and Drug Administration (FDA) does not regulate supplements the way it regulates prescription drugs. That means some supplement products may not contain what the label says. When choosing a supplement, look for independently tested products and consult a healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Lindsey DeSoto

By Lindsey DeSoto, RD, LD

Lindsey DeSoto, RD, is a registered dietitian specializing in nutrition and health and wellness content.