Calcium for Bearded Dragons

Calcium for Bearded Dragons

Calcium is vital for bearded dragons, but understanding why and just how much beardies need can easily become overwhelming for any owner. Fortunately, this article gives you everything needed to understand calcium needs for beardies.

Demystifying Calcium

Many owners can feel overwhelmed trying to understand how to give their beardie the calcium they need. What seems to be an easy subject quickly turns to confusion when vitamin D3, UV exposure, and phosphorus start being discussed. If this is you, fear not. This one section should answer all your questions so you never second guess your bearded dragon's calcium regime in the future.

Calcium and Vitamin D

Vitamin D is required for calcium absorption to occur. This means bearded dragons that don't receive enough vitamin D will eventually develop a calcium deficiency. The first step to make sure your beardie has enough calcium is providing them with vitamin D. Below are the best sources of vitamin D.

Natural Sunlight

Bearded dragons are adapted to use the sun as their primary source of vitamin D. This is the best source of vitamin D. The UVB rays from natural sunlight are converted to vitamin D3 which they use to absorb calcium. Keep the following in mind if you're planning on using sunlight to provide vitamin D to your beardie:

  • Your beardie must be in direct sunlight outside. The sun's UVB rays which generate vitamin D is blocked by glass and windows. So placing your beardie next to a window will not provide any vitamin D.
  • Watch out for predators. Dogs, cats, and large birds may prey on your bearded dragon so monitor them while they are outdoors.
  • Watch the weather. If it's wet, cold, or humid your beardie should stay inside. If it's too hot your bearded dragon will need a place to cool down.
  • Vitamin D supplements are not necessary on days your beardie has been outside in direct sunlight for 30 minutes.
UVB Bulbs

UVB bulbs mimic the sun's natural UVB rays which provide bearded dragons with a source of vitamin D3. These bulbs are required for all bearded dragons kept indoors. Keep the following in mind with UVB bulbs:

  • UVB light is invisible to humans, so an illuminated tank does not guarantee UVB is reaching your beardie.
  • UVB bulbs lose their strength overtime and should be replaced regularly. Cheaper UVB bulbs have a lifespan of 6 months whereas higher quality UVB bulbs can last as long as a year before needing to be replaced.
  • Mesh screens commonly placed on top of tanks block up to 30% of UVB. If you cannot safely place the UVB bulb directly inside your beardies tank, carefully trim or cut the screen away from the bulb so your beardie can receive the bulb's full strength.
  • Glass and clear plastic block 100% of UVB light. There cannot be any glass or plastic between the UVB bulb and your beardie.
Vitamin D Supplements

If your beardie stays mostly indoors you should also use a vitamin D supplement. Supplements by themselves cannot provide all the vitamin D your bearded needs so they should be used in combination with UVB bulbs.

Calcium and Phosphorus

Both calcium and phosphorus are minerals that occur naturally in food. However, they have a unique relationship as phosphorus blocks calcium from being absorbed. This means foods high in phosphorus can block all the calcium in that meal from being absorbed. One way to look at it is to assume each mg of phosphorus will block one mg of calcium.

This ratio of calcium to phosphorus is displayed as Ca:P and the ideal ratio is 2:1 (which is twice as much calcium as phosphorus). Not every meal has to be the perfect ratio, some meals can contain more or less calcium than desired. The easiest way to keep your beardies calcium and phosphorus levels balanced is to look at the previous week's diet and make adjustments where needed. Below are some tips:

  • Use a calcium supplement with their existing diet to provide additional calcium without altering the diet
  • Introduce new foods that are high in calcium but low in phosphorus

How Much Calcium Do Bearded Dragons Need?

The calcium needs for a bearded dragon depend on many things. In this section we go over those things and explain two ways you can verify your beardie is receiving enough calcium.

The Easiest Way to Meet Calcium Needs

A balanced diet is the easiest way to meet your beardies calcium needs. When each meal is balanced your beardie will receive the correct ratio of nutrients regardless of how much or little they choose to eat. This is the easiest and healthiest way to meet your beardies calcium needs and it can be done by following the two steps below.

Step 1) Provide Sufficient UVB

As previously discussed, bearded dragons needs UVB light to absorb calcium. Basically their body converts UVB into vitamin D3, which is required for calcium absorption. Bearded dragons with correct UVB lighting can absorb more calcium from food which reduces the frequency of calcium supplements. For clarification, correct UVB lighting means:

  • Replacing your UVB bulbs every 6 months (or however long the manufacturer states they are good)
  • Allowing direct exposure to UVB light - meaning no mesh screens or glass tops are between your bearded dragon's scales and the UVB bulb
Step 2) Prepare Meals with Correct Calcium to Phosphorus Ratio

This step may take a little time to plan, but is easy to execute. Create a meal plan for your beardie with the goal of each meal containing 1.5-2x more calcium that phosphorus. It is probably easiest to start with one of the meals you normally feed your beardie and making slight adjustments to get the Ca:P ratio correct. Once done, each serving will provide your beardie with the correct ratio of nutrients needed to stay healthy. There's no need to manually calculate the calcium requirements.

Manually Calculating Bearded Dragon Calcium Needs

If you prefer, you can manually calculate the calcium your beardie needs. The amount of calcium your bearded dragon needs depends on several variables including your beardies age, the amount of phosphorus in their diet, and the level of vitamin D they can absorb.

Calcium Requirements by Age

The below table shows the estimated daily calcium a healthy bearded dragon needs by age. It's important to remember that bearded dragons can be picky eaters and they may choose to eat more or less depending on their mood. So it's easier to use these amounts as more of a daily average rather than an exact amount.

AgeCalcium Per DayHatchling650mgJuvenile800 to 1,100mgYoung Adult1,000 to 1,300mgAdult1,200 to 1,500mg

Phosphorus Consumption

Phosphorus blocks calcium from being absorbed. This means foods containing more phosphorus than calcium will actually block calcium from other foods in the meal. A trick is to assume each mg of phosphorus will block one mg of calcium from being absorbed. So look up and record both the calcium and phosphorus in your beardies most recent meal. Then subtract the mg of phosphorus from the mg of calcium and that tells you how much calcium is actually available for absorption. For example, 100g of kale contains 254mg of calcium and 55mg of phosphorus - so kale will provide 199mg of calcium per 100g serving.

Vitamin D

Vitamin D comes from sunlight, UVB bulbs, and supplements and is required for calcium absorption. Without vitamin D bearded dragons cannot absorb calcium and will pass most of the calcium from their diet in urine and stool. The easiest way to compensate for vitamin D is by using a calcium powder supplement. The amount and frequency depends on how much vitamin D your beardie receives.

  • Bearded dragons that receive natural sunlight get enough vitamin D from the sun and do not need calcium supplements as long as their diet contains the calcium they need
  • Bearded dragons that are kept indoors and use UVB bulbs will need calcium supplements.

Calcium Calculator

We know this is a lot to take in, so we've created a calcium calculator below that should do most of the work for you. Simply provide your beardies age, UVB exposure, and the amount of phosphorus in the food your beardie normally eats and the calculator will do the rest. It will tell you both how much calcium to include in your beardies diet and how frequently you need to use calcium power.

Calculate Daily Calcium Needs

See how much calcium and supplements your bearded dragon needs each day.

Reptile Age:
UVB Exposure:
Phosphorus in Diet:

Calcium Powder Frequency

You should plan on using a calcium powder supplement in addition to calcium-rich foods to make sure your beardie is receiving enough calcium. It's easier to adjust the frequency calcium supplements are used rather than attempting to calculate the exact mg of calcium powder your bearded dragon ingests.

The frequency you use calcium powder depends on your bearded dragon's age and how much Vitamin D3 they receive. Bearded dragons receive enough calcium from their diet.

  • Younger bearded dragons need more calcium so their bones develop correctly while they are growing.
  • Dragons receiving low to moderate vitamin D3 cannot absorb as much calcium from their diet, so they will need to be given calcium more frequently.
  • Adult dragons receive most of the calcium they need in their diet so they need to be given calcium supplements less frequently than than juveniles.
  • Dragons receiving high levels of vitamin D3 absorb higher amounts of calcium from their diet, so they need supplements less frequently.

Bearded dragons receive high levels of D3 if they sunbathe outside or if their tank uses a mercury vapor UVB bulb that is not blocked by a screen, plants, or glass. The high levels of vitamin D3 they will absorb higher levels of calcium so you will want to reduce the frequency you use calcium supplements. This will prevent your beardie from getting sick from receiving too much calcium.

AgeModerate D3High D3HatchlingDaily4 to 5 times per weekJuvenile3 to 4 times per week3 times per weekAdult1 to 2 times per weekOnce every two weeks
Bearded Dragons and Phosphorus

Discover how much phosphorus your beardie needs to stay healthy.

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About this Article

Authored by:The Bearded Dragon
Updated:December 29, 2022
This article has been edited 22 times since first published. Please let us know of any suggestions or improvements.
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