A high percentage of adults, somewhere between 50 percent and upward of 90 percent depending on ethnicity and location, are believed to be at least somewhat deficient in vitamin D. It makes sense then that vitamin D is now one of the most widely consumed supplements, though you may wonder how much vitamin D should I take. It’s a tricky question, but it’s important to get enough of this essential vitamin.
Deficiency in vitamin D is a real problem considering that this nutrient has been shown to promote health by helping with absorption of minerals like calcium, aiding in bone health, boosting immune function, supporting growth and development, and much more. If you spend little time outdoors in the sun, have dark skin, are over the age of 70 or live in northern regions of the world where there’s less sunshine year-round, then you’re more likely to experience vitamin D deficiency symptoms.
When it comes to reaping the many benefits of vitamin D, you may be wondering “how much vitamin D should I take?” The optimal amount of vitamin D to take in supplement form depends on a number of factors — for example, if you’re already deficient in vitamin D, your diet, age, health status, where you live and so on. As you can see, answering the question of how much vitamin D I should take isn’t necessarily cut and dry.
Role of Vitamin D
Vitamin D is a fat-soluble vitamin that has many roles throughout the body, some of which include:
- Helping calcium be absorbed into the bones and preventing fractures, bone loss, etc.
- Managing blood sugar levels and normalizing insulin secretion
- Regulating blood pressure, cholesterol levels and inflammation
- Controlling release of parathyroid hormone
- Supporting the immune system by preventing prolonged or excessive inflammatory responses
- Facilitating brain function and preventing mood disorders, including depression and seasonal affective disorder
- Regulating sex hormone production, including testosterone levels
- Improving nerve and muscle function
- Reducing the risk for many types of cancer by influencing cell differentiation and tumor growth
Vitamin D is unique because our bodies make most of our vitamin D on their own when exposed to the sun, rather than getting vitamin D from foods. When UV-B sunshine rays land on the skin, a substance in the skin called 7-dehydrocholesterol is literally converted into vitamin D3.
There’s evidence that vitamin D may help defend against many symptoms and conditions, including heart disease, cancer, diabetes, bone loss and depression.
On the other hand, vitamin D deficiency is correlated with an increased risk of many common health conditions. About 1 billion people worldwide have vitamin D deficiency according to scientific studies and reviews. Vitamin D deficiency symptoms can be linked to the following health problems:
- heart disease
- high blood pressure
- autoimmune diseases
- chronic pain
- infectious diseases
- and more
How Much Vitamin D Should I Take for Optimal Health?
Your need for vitamin D goes up if any of these factors apply to you:
- You know you’re already deficient in vitamin D
- You have dark skin
- You’re an older adult over 70 (since the production of vitamin D from the skin decreases with age). Infants, children and older adults are all at risk for low vitamin D.
- You spend little time outdoors or always wear sunscreen when exposed to sunlight
- You’re a shift worker, health care worker or another “indoor worker,” which means you get little outdoor time and sunlight exposure
- You’re overweight or obese (since vitamin D can accumulate in body fat)
- You are a nursing home resident or hospitalized patient
- You have a health condition, such as celiac disease, Crohn’s disease or cystic fibrosis, that interferes with absorption and processing of vitamin D in the intestines, kidneys or liver
- Breast-fed infants are also at risk for vitamin D deficiency, which is why supplementing is recommended
How much vitamin D should women take per day?
According to the USDA and National Institutes of Health, the standard recommendation of vitamin D that adult women should take in order to prevent deficiency is between 600 to 800 international units per day, depending on age. The exact number is debatable, and some experts feel that a higher dose of vitamin D, around 2,ooo to 5,000 IU per day, may be more beneficial.
How much vitamin D should men take per day?
The standard recommendation for adult men is also between 600 to 800 IU of vitamin D per day. Adults over 70 should supplement with more, at least 800 IU per day, while younger adults need at least 600 IU daily.
Is it OK to take vitamin D every day?
Yes, assuming you don’t take high doses that exceed 5,000–10,000 IU/day.
What Are the Optimal Blood Levels of Vitamin D?
To find out if you are deficient in vitamin D your doctor can order a blood test, called a 25-hydroxy vitamin D test.
- Vitamin D levels should be above 20 nanograms (ng) per milliliter (mL) of blood, which indicates that you aren’t suffering from severe vitamin D deficiency.
- A level of 50+ ng/mL indicates a good level of vitamin D, while 30–50 ng/mL means you want to supplement with vitamin D, work on spending more time in the sun and adding vitamin D foods into your diet.
- “Subclinical” vitamin D deficiency is thought to be very common. It is defined as a lower than normal vitamin D level that has no visible signs or symptoms. Levels below 30 ng/mL indicate vitamin D insufficiency.
- A level less than 20 to 30 ng/mL means you are very deficient and definitely want to take immediate action to bring those levels up.
- On the other hand, vitamin D toxicity (too much vitamin D in the blood) is considered anything above 200–240 ng/mL of blood.
How Much Vitamin D Should I Take for Specific Conditions?
How much vitamin D should I take if I’m deficient?
If a blood test has revealed that you’re low in vitamin D, you can either take smaller doses for a long period of time to bring your level up, such as 5,000 to 10,000 IU per day, or a high dose administered over the course of several weeks. For adults with low vitamin D levels, the Endocrine Society recommends taking at least 1,500–2,000 IU per day.
If you’re taking a very high dose all at once, such as more than 40,000 IU, then it’s possible that side effects may occur due to “vitamin D toxicity.” The best thing to do is talk with your doctor about supplementing with higher doses of vitamin D if you are severely deficient or have a very low level according to a blood test.
How much vitamin D should I take for depression?
There’s some evidence that low vitamin D levels are linked with depression, although this doesn’t mean that vitamin D deficiency causes depression. Rather, it’s speculated that people who don’t spend much time outside or eat vitamin D foods may also be more likely to develop depression. The dosages of vitamin D used in studies that have focused on depression have varied, typically between 600 IU/day (the standard recommendation) to 4,000 IU/day.
How much vitamin D should I take to lose weight?
Taking vitamin D won’t necessarily lead to weight loss, but deficiency in vitamin D has been linked to a higher risk for obesity. Researchers believe that vitamin D may help prevent obesity in a number of ways, such as by regulating hormones and neurotransmitters, including hunger hormones, serotonin and testosterone. The goal should be to maintain adequate blood levels of vitamin D, which means taking at least 600 IU daily and possibly higher doses (5,000 to 6,000 IU/day) if needed.
How Much Vitamin D Should I Get from the Sun?
In addition to wondering how much vitamin D should I take, many people wonder how much vitamin D should I get from the sun.
There’s a reason that vitamin D is referred to as “the sunshine vitamin.” Sunlight exposure on our bare skin is the single best way to get enough vitamin D. Unfortunately most people today don’t spend enough time in the sun, due to factors like working long hours inside, living in cold climates, being afraid of sunburns, etc.
In order to get enough vitamin D naturally from the sun it’s important to get outside and expose your skin to sunlight, without sunscreen. Aim to spend about 10–20 minutes in the sun daily with as much of your bare skin exposed as you can, which will help your body produce vitamin D. You will absorb the most sunlight between about 11 a.m. and 3 p.m.
Melanin is a substance that affects how light or dark your skin color is. The amount of melanin you have in your skin also affects the amount of vitamin D you can produce, so the fairer your skin, the more easily you can make vitamin D. If you have dark skin, you will likely need more time in the sun, roughly 40 to 60 minutes daily, to make enough vitamin D.
Eating vitamin D-rich foods like eggs, raw milk and fish can also helps improve your blood levels of vitamin D.
Sources and Dosage
Below are general recommendations for supplementing with vitamin D3 if you’re wondering how much vitamin D should I take:
- Children younger than 5: Up to 35 units per pound/day can usually be safely taken.
- Children ages 5–10: About 400 IU daily. Up to 2,500 units/day can usually be safely taken.
- Adults/pregnant women/breast-feeding women: Between 600–800 IU per day. Up to 5,000 units/day can be safely taken.
There are two forms of vitamin D supplements: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
The type of vitamin D our bodies naturally make is called cholecalciferol, which is vitamin D3. The body is able to convert some D2, which is a manmade form of vitamin C, to be used for body functions, but still our bodies prefer to use vitamin D3. D3 supplements are derived from animal products that contain cholesterol and are very similar to the type we make ourselves, more so than D2 (or ergocalcifero), which is not as absorbable.
In people whose vitamin D levels are normal, a common recommendation is to take a dose of 800 international units of vitamin D per day. This dose may be enough to help you maintain levels in the normal range, but some studies suggest that higher doses may be needed by many people.
Is it safe to take 5,000 IU of vitamin D3 daily? Research suggests there is little risk associated with taking around 5,000 IU of vitamin D3 daily, but some people may do best with a higher or lower amount depending on their health status. However, some health authorities recommend taking no more than 4,000 IU daily for an extended period of time, even though research indicates that 10,000 IU per day typically causes no adverse reactions. This makes it a little tricky to find the best answer on how much vitamin D should I take with such a large range.
Is the best time to take vitamin D the morning or night? Taking vitamin D supplements with a meal may help with absorption, however there isn’t solid evidence that supplements work better when taken at certain times. Some researchers advocate taking vitamin D in the morning in order to prevent any side effects that may disturb sleep.
Risks and Side Effects
What happens if you take too much vitamin D? Can you overdose on vitamin D?
Taking high doses of vitamin D causes your liver to produce a chemical called 25(OH)D, which makes calcium accumulate in your bloodstream. You’re most likely to experience symptoms of too much vitamin D when taking supplements in high doses for a long period of time. This can potentially cause side effects if levels of 25(OH) in the blood become elevated.
Potential side effects can include high blood calcium levels; exhaustion; abdominal pain and digestive issues like nausea, constipation, diarrhea or loss of appetite; increased thirst and dry mouth; and possibly kidney stones. The best way to avoid experiencing vitamin D toxicity is to not take very high doses of vitamin D in supplement form, such as 10,000 IU per day for more than several days in a row. Instead, get the vitamin D you need from sunlight, a healthy diet and supplements in the recommended dosage range.
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