Vitamin D2 is suitable for people with low vitamin D levels. But there are many different ways to supplement vitamin D levels. There are actually two different versions: vitamin D2 (D2) and vitamin D3 (D3).
So what's the difference? Which one is better? Here, we’ll clear up the confusion about vitamin D supplements and explain why some people take vitamin D2.
What is vitamin D? How to get it?
Vitamin D is an important component of many different cellular processes in the body. It's known to keep bones strong, but it also plays a role in other functions, including:
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muscle power
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immunity
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Calcium and glucose metabolism
There are two natural sources of vitamin D:
1) Food : Only a few foods naturally contain vitamin D. Some of the best sources include:
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liver
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oily fish
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mushroom
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yolk
Foods artificially fortified with vitamin D are common, such as cereals and milk.
2) Sunlight : Our bodies can actually make their own vitamin D! When we are exposed to the sun's ultraviolet (UV) rays, our skin uses sunlight to make vitamins from scratch.
Most people get enough vitamin D from these two sources. After all, your body can absorb enough sunlight with just 5 to 30 minutes of sun exposure each day. But some people choose to take supplements to keep their vitamin D levels at normal levels, especially if they have low vitamin D levels or are at risk for low vitamin D levels.
What is vitamin D2? Is it better than vitamin D3?
The supplement contains two types of vitamin D:
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Vitamin D2, also known as ergocalciferol
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Vitamin D3, also known as cholecalciferol
They are very similar molecules and both are easily absorbed by the body.
There was a time when these two forms of vitamin D were considered equivalent and interchangeable. But now we know that's not entirely the case. Evidence shows that D2 is actually less effective at raising vitamin D levels than D3 and has a shorter duration of action. So, while both can be used as supplements, D3 appears to be slightly better than vitamin D2 .
Given that D3 appears to be the better supplement option, you may wonder why providers prescribe vitamin D2. The answer lies in the available formulations of vitamins, which we will explore next.
Do I need a prescription to take vitamin D?
Depending on the strength of vitamin D2 or D3 you are looking for, you may not need a prescription. Dosages for over-the-counter (OTC) preparations are the following , measured in International Units (IU):
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400 international units
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800 international units
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1000 international units
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2000 international units
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5000 international units
If someone has low vitamin D blood levels, their provider may recommend taking a more concentrated supplement (50,000 IU) for a short period of time to bring their levels back into the normal range.
Although both vitamin D2 and D3 pills are available in this strength, many medical providers will prescribe D2 because it is more readily available and easier to find. Interestingly, the same dose of D3 can be purchased without a prescription. But most pharmacies don't sell it, and many companies will only sell it to licensed health care providers.
It's also important to know that while these ultra-high doses are sometimes used intermittently to boost vitamin D levels, this is a controversial method. This is because there has never been strong evidence that they are more effective than smaller, more conservative doses.
Do I need to take vitamin D supplements?
There are many reasons why someone takes vitamin D supplements. Of course, the most common cause is low vitamin D levels .
People may have low vitamin D levels for a variety of reasons:
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Low dietary intake : Most people do not have foods rich in liver and mushrooms in their diets. Young infants are particularly at risk for low vitamin D levels due to low dietary intake.
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Low sun exposure : This condition is common in winter and in climates and latitudes with limited sunlight. Otherwise, people with lifestyles that involve spending more time indoors are also at risk for lower vitamin D levels.
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Darker skin : People with highly pigmented skin produce less vitamin D when exposed to sunlight.
People with certain medical conditions also often take vitamin D supplements, often as a preventive measure to help strengthen bones. Some examples include:
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Rickets : This is a long-term deficiency of vitamin D in children.
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Osteoporosis in adults with osteoporosis : This is a common disease in which bones lose their strength. It usually affects people as they age, but is more common in women.
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Hypoparathyroidism : This condition is caused by low levels of parathyroid hormone (PTH). This hormone helps bones release calcium into the bloodstream when calcium levels are low. If you don't have enough PTH, your calcium levels may drop, affecting your bone strength. Taking vitamin D helps your body absorb more calcium , which strengthens your bones.
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Familial hypophosphatemia : This is a genetic disorder that causes low levels of phosphate in the blood (which is also important for bone health). Vitamin D helps increase these levels.
Recommended daily intake of vitamin D
Recommended doses of vitamin D vary by age. Experts recommend daily dosage:
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400 IU for infants under 12 months
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People between 1 and 70 years old need 600 IU
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People 71 and older need 800 IU
As you can see, these doses are much lower than the 50,000 IU concentrated supplement typically recommended for people with low vitamin D levels.
Is too much vitamin D harmful to the body?
Too much vitamin D can be harmful. This is because it causes abnormally high levels of calcium in the blood, which can lead to:
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Nausea, vomiting, or abdominal pain
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dehydration or excessive thirst
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kidney stones
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confusion and hallucinations
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muscle weakness and drowsiness
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arrhythmia
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kidney failure
If you're wondering whether you should take vitamin D supplements, it's always helpful to ask your healthcare provider. They can help you determine your individual vitamin D needs.
generalize
Vitamin D plays an important role in bone health, and most people get enough vitamin D from food and sunlight. However, some people can benefit from additional supplements to ensure they have enough vitamin D to keep their bones and muscles strong. When comparing vitamins D2 and D3, there is evidence that D3 is the better choice for an effective supplement. But if your doctor recommends taking a highly concentrated dose for a short period of time, they may prescribe vitamin D2 to make sure you can easily find a supplement.
