box turtle calcium supplement

Box turtles are relatively easy to care for since they don’t require a tank full of water. One of the most important aspects of caring for a box turtle is making sure they are fed a healthy, balanced diet. While box turtles are omnivores and eat both plant and animal matter, people forget about the importance of calcium. In today’s article, we will review the best box turtle calcium supplements and why calcium is so important for box turtles.

Box turtle calcium supplements

The three best calcium supplements for box turtles are Zoo Med Calcium, Reptile Calcium Stones, and T-Rex Calcium Plus.

Zoo Med Calcium for Box Turtles

Zoo Med is one of the most popular reptile brands, and their calcium supplements are top of the line. This calcium carbonate comes in a powder that you sprinkle on your box turtle’s food. Along with calcium, this supplement includes vitamin D3, which is used to help your box turtle synthesize calcium.

The best part about this supplement is that it’s very cheap. At the time of this writing, it costs less than $3.

Reptile Calcium Stones for Box Turtles

This is a great option if you want to give your box turtle something to chew on. This calcium block is a great source of calcium and gives your box turtle something to keep them entertained. The only downside is that your turtle might not like the taste.

If this happens, you can also just put the cube in their water and it will dissolve.

T-Rex Calcium Plus

This calcium powder is designed specifically for box turtles. Similar to the Zoo Med Calcium supplement, it is a powder that you can spread on your turtle’s food. While I haven’t used it personally, some people have mentioned that their turtles actually like the taste.

Along with calcium, this supplement is also a good source of vitamin A.

How much calcium powder to give a box turtle

You should always follow the instructions on the calcium supplement bottle. That being said, most calcium powders recommend that you give your box turtle 1 teaspoon for every 10 ounces of weight per week.

Baby box turtles typically weigh around 8-10 ounces, while adult box turtles can weigh around 25-32 ounces. You can learn more in my article on how big do box turtles get.

Now let’s talk about why calcium is so important for box turtles.

Why Do Box Turtles Need Calcium Supplements?

Calcium plays a very important role when it comes to the growth and development of your box turtle’s bones. One of your turtle’s most important bones is their shell. They can experience a wide range of health defects if they don’t receive enough calcium.

What happens if your box turtle doesn’t get enough calcium?

If your box turtle develops a calcium deficiency, it can result in a wide range of health issues. It will likely lead to a weak or deformed shell. Your turtle will also be susceptible to metabolic bone disease, which can eventually lead to death.

Types of Box Turtle Calcium Supplements

There are three main types of calcium supplements for box turtles: calcium powder, calcium blocks, and soluble calcium.

I have found that calcium powder is the best because it is the easiest to hide in their food. Most calcium powder consists of calcium carbonate, and it can be easily sprinkled onto your box turtle’s food.

Calcium blocks are another good way to supplement your box turtle’s diet. However, not every box turtle will like the taste of the calcium block. Therefore, it might be a waste if you get a calcium block just to find out your turtle wants nothing to do with it.

There are also some calcium supplements that can be mixed in with your box turtle’s water. While this is pretty easy to get your turtle to consume, there aren’t a lot of liquid calcium products on the market.

Along with supplementing your box turtle’s diet with calcium supplements, you should also try to feed them fruits and vegetables that are high in calcium.  

Fruits and vegetables that are high in calcium

Leafy dark vegetables tend to have high calcium contents. Some good options to feed your box turtle include kale, cabbage, and collard greens.

In terms of fruit, some good options are kiwi, blackberries, strawberries, and raspberries.

To learn more, check out my article on what fruits and vegetables can box turtles eat.

Don’t give your box turtle too much calcium

While calcium is essential for your box turtle’s health, just like anything else, too much of it can be harmful. Excessive calcium intake can lead to bladder stones or even kidney damage. It can also lead to digestive issues. While your box turtle will likely not overdose on calcium from natural foods, it can happen if you overfeed them calcium supplements.

In extreme cases, they can also develop shell pyramiding.

For this reason, you should make sure to always follow the dosages that are listed on the calcium supplements.


Along with their regular diet, it is important that you ensure your box turtle gets enough calcium. While they can get the majority of their calcium from plants, it is recommended to supplement their diet with calcium supplements. This will help them maintain strong and healthy bones.

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