Recommended Vitamin D Daily Intake By Age | |
---|---|
Age | Recommended Amount |
Birth to 12 months | 10 mcg (400 IU) |
Children 1 to 13 years | 15 mcg (600 IU) |
Teens 14 to 18 years | 15 mcg (600 IU) |
Adults 19 to 70 years | 15 mcg (600 IU) |
Adults 71 years and older | 20 mcg (800 IU) |
Pregnant or lactating teens and adults | 15 mcg (600 IU) |
How Much Vitamin D Do Women Need per Day?
Why Vitamin D Is Important
Vitamin D assists in many vital body functions, one of the most important being its role in bone health.
Vitamin D promotes calcium absorption and helps the body maintain adequate levels of calcium and phosphorus in the blood. The body needs both nutrients for healthy bones and teeth. Optimum vitamin D, along with calcium, can also reduce the risk of osteoporosis (progressive bone loss) in older adults.
Additional benefits of vitamin D are:
- Promotes healthy muscles function
- Supports immune health
- Reduces the risk of severe illness
- Regulates mood and reducing depression
- Reduces fibromyalgia risk and symptoms
- Reduces the risk of heart disease
- Supports weight loss efforts and reduces inflammation
- May reduce the risk of cancer death
Vitamin D may promote healthy muscle function since a lack of vitamin D is known to weaken muscles.
Vitamin D can support immune health since people who do not get enough vitamin D may be at an increased risk for infections and autoimmune and immune-mediated diseases like type 1 diabetes, multiple sclerosis (MS), rheumatoid arthritis (RA), systemic sclerosis, systemic lupus erythematosus (lupus), and inflammatory bowel disease (IBD).
While research results are mixed, some studies suggest that vitamin D reduces the risk of severe illness, including from influenza (the flu) and COVID-19 infections. Low vitamin D levels may contribute to acute respiratory distress, while optimal levels can reduce respiratory distress linked to respiratory infections.
Research has found that vitamin D may play a vital role in regulating mood and reducing depression risk. One 2020 review of 7,534 people experiencing negative emotions found that vitamin D supplementation led to symptom improvement. Vitamin D supplementation can also help people with depressive symptoms related to vitamin D deficiency.
Low vitamin D may be a risk factor for fibromyalgia, a musculoskeletal disorder that causes widespread body pain. It is also linked to worsening pain, anxiety, and depression symptoms in people with fibromyalgia. Keeping vitamin D levels balanced could lead to symptom improvement or reduced risk.
Low vitamin D levels have been linked to heart disease conditions like hypertension (high blood pressure), heart failure, and stroke, suggesting that adequate supplies of vitamin D may reduce the risk of heart disease. However, it is unclear whether vitamin D deficiency contributes to the development of heart disease or if it's an indicator of poor health in chronic disease.
Vitamin D may support weight loss efforts and reduce inflammation since research has found that people who have obesity may have lower vitamin D levels. Research shows that dietary changes and weight loss can improve vitamin D levels. Weight loss and vitamin D supplementation can also reduce levels of meta-inflammation (low levels of chronic inflammation). No research studies have suggested that vitamin D supplements or vitamin D can help you lose weight.
Some clinical studies suggest that vitamin D supplementation may slightly reduce the risk of dying from cancer. More research is needed.
The Best Time of Day to Take Vitamin D, According to Science
What Happens When Levels Are Abnormal?
Not enough vitamin D may lead to deficiency, while too much vitamin D may lead to toxicity.
Vitamin D Deficiency
Levels lower than 20 ng/mL of vitamin D a deficiency. Some people may be at a higher risk for deficiency due to their inability to get enough vitamin D from sunlight.
Who Is at Risk for Vitamin Deficiency?
Some people are at a higher risk for vitamin D deficiency.These groups include:
- People who use sunscreen: The use of sunscreen with a sun protection factor (SPF) of 15 or higher may reduce the body's vitamin D3 production.
- People with limited sun exposure to their skin: This includes people who spend most of their time indoors, live in buildings blocked from sunlight, or wear body and head coverings that limit skin exposure to sunshine.
- People who have darker skin: The higher the melanin (skin pigment), the less vitamin D the skin absorbs.
- Breastfed infants: Human milk alone does not provide infants with enough vitamin D. It is recommended that infants are given 400 IU of vitamin D supplementation daily.
- Older adults: As people age, their skin's ability to make vitamin D from sunlight exposure starts to decline.
- People with health conditions that limit fat absorption, such as celiac disease, Crohn's disease, or ulcerative colitis: These conditions also cause poor absorption of vitamin D from food.
- People with obesity or who have undergone gastric bypass surgery: Both need more vitamin D.
These factors can increase the risk of vitamin D deficiency. Therefore, getting vitamin D from sources other than sunlight, including diet and supplements, is essential.
Most people with vitamin D deficiency don't have any symptoms. Others may notice vague symptoms.
Symptoms of a vitamin D deficiency may include:
- Muscle pain and/or muscle weakness
- Bone pain
- Muscle spasms
- In children, rickets with skeletal deformity
Vitamin D Toxicity
Vitamin D toxicity, also called vitamin D intoxication or hypervitaminosis D, is rare. However, it can cause serious health problems if left untreated. It can occur if someone has taken too much vitamin D from over-the-counter (OTC) supplements or prescription vitamin D.
The main complication of vitamin D toxicity is hypercalcemia, which is higher-than-normal levels of calcium in the blood. Hypercalcemia causes the symptoms of vitamin D toxicity.
Symptoms may include:
- Confusion
- Constipation
- Dehydration and increased thirst
- Frequent urination
- Kidney stones
- Lethargy (fatigue, drowsiness, and lack of energy or mental awareness)
- Loss of appetite
- Muscle weakness, which may lead to difficulty with walking
- Nausea and vomiting
Treatment for vitamin D toxicity involves lowering the levels of calcium in the blood. This typically is done by:
- Stopping vitamin D and calciumsupplements
- Intravenous (IV, within a vein) fluids for dehydration
- Corticosteroids and bisphosphonates to block bone resorption (the breakdown of bone tissue and release of minerals into the bloodstream)
Vitamin toxicity can be prevented by not taking vitamin D supplements if you have normal levels and not taking more than a healthcare provider recommends.
If you are taking prescription vitamin D supplementation, your healthcare provider will regularly check your vitamin D levels. Keep vitamin D supplements and prescriptions out of reach to prevent toxicity in children.
Vitamin D Levels for Healthy Bones
A vitamin D level of 20 ng/mL or higher is considered sufficient for good bone health. However, a level below 20 ng/mL is considered insufficient, and below 12 ng/mL is considered deficient, which could lead to adverse effects.
Left untreated, vitamin D deficiency could lead to severe bone disorders, such as rickets or osteomalacia.
How to Get Your Levels Checked
Your healthcare provider can determine if you are getting enough vitamin D using the 25-hydroxy vitamin D blood test.
If you prefer to check your vitamin D levels at home, test options are available. Most are self-collected tests using a finger-prick blood sample. Once you have a sample, you can ship it to a lab and wait for results, which could take days or weeks. You will receive the results in an easy-to-read report or by speaking with medical personnel at the lab.
If your vitamin D blood levels are low, your healthcare provider may recommend supplementation. Vitamin D is found in both multivitamins and vitamin D supplements. Your provider can make recommendations based on your individual vitamin D needs.
Ways to Boost Your Vitamin D Levels
You may be able to get more vitamin D by spending more time in sunlight. Other methods include supplements and eating vitamin D-rich foods.
Sunlight Exposure
Vitamin D is often called the "sunshine vitamin" because the sun is one of the best sources of vitamin D.
The skin contains 7-dehydrocholesterol, a type of cholesterol that assists in vitamin D production. When this compound is exposed to UV-B radiation from the sun, vitamin D is created.
Vitamin D derived from the sun can circulate much longer than vitamin D from supplements or food. Even so, the amount of vitamin your body creates depends on factors like age, skin pigmentation, geographical location, sunscreen use, the clothes you wear, and health conditions that may hinder vitamin D processing in the body.
Vitamin D-Rich Foods
Many foods are rich in vitamin D, and their consumption can help you to maintain adequate vitamin D levels. Some foods rich in vitamin D are:
- Fatty fish: Such as trout, salmon, tuna, and mackerel, which are among the best food sources of vitamin D
- Fish liver oils: Such as cod liver oil
- Vitamin D-fortified milk: Such as fortified milk (containing about 120 IU of vitamin D per cup) and including plant-based alternatives like soy, almond, and oat milks
- Vitamin D-fortified foods: Examples of which are breakfast cereals, orange juice, yogurt, and margarine
- Beef liver, egg yolks, and cheese: Contain small amounts of vitamin D
- Mushrooms: Contain some vitamin D, with higher amounts in those labeled as having UV exposure as those have more vitamin D
Vitamin D Supplements
Vitamin D supplementation might be the best way for many people to get sufficient amounts of the nutrient. Your healthcare provider can check your vitamin D levels and recommend OTC or prescription vitamin D supplements.
In the United States, the Food and Drug Administration (FDA) does not regulate dietary supplements in the same way it does for medications. When deciding to supplement with vitamin D, you will want to discuss with a healthcare provider what your levels are and whether you need supplementation.
If you and your healthcare provider decide that OTC supplements are a good option, look for products that are independently tested and certified by organizations likeNSF,U.S. Pharmacopeia (USP), orConsumerLab.com.
Vitamin D2 vs. Vitamin D3
There are two main types of vitamin D supplements—D2 (ergocalciferol) and D3 (cholecalciferol). D3 might raise blood levels of vitamin D higher and for a longer time than D2.
These vitamins are fat soluble, so they should be taken with a meal or snack that includes some fat for better absorption.
When to Contact a Healthcare Provider
If you are concerned you are not getting enough vitamin D or you think your body is not using it correctly, talk to a healthcare provider. This is especially important if you have risk factors for vitamin D deficiency.
A healthcare provider can check your vitamin D levels and tell you whether they are in the healthy range or if supplementation is necessary.
Summary
Vitamin D is an essential nutrient your body needs for bone health and various body functions. You can boost your vitamin D levels by getting enough sunlight and eating foods rich in vitamin D.If you think you may be low in vitamin D, consult a healthcare provider. They can perform a blood test to check your levels and recommend supplementation if necessary.