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Can You Give A Leopard Gecko Too Much Vitamin D3?

Leopard gecko D3 overdose

If, like me, you’re wondering whether you can give your leopard gecko too much vitamin D3 – and if that is a bad thing – keep reading as this is very important to know for your gecko. 

Yes, you can give a leopard gecko too much vitamin D3. A Vitamin D overdose in leopard geckos can lead to calcification of their organs and, ultimately, to their death. 

Because it is so important to give your leopard gecko the correct amount of vitamin D3, I decided to have a deeper look at overdoses and how to prevent it.  

Leopard Gecko D3 Overdose

The symptoms of a vitamin D3 overdose can be difficult to spot in some cases as there isn’t one specific sign of D3 overdose, but rather a number of them that together point to an overdose. 

Symptoms Of A Vitamin D3 Overdose

The symptoms a vitamin D3 overdose include:

  • anorexia (or a lot of weight loss)
  • lethargy
  • more urine than normal 
  • malaise 

These symptoms and your leopard gecko seeming “off” will worsen over time if the overdosing with vitamin D3 continues. This is especially prone to happen if a vitamin D3 supplement is the main source of D3 for your leopard gecko.

What To Do If You Suspect A Vitamin D3 Overdose

If you suspect a vitamin D3 overdose, you need to get your leopard gecko to the vet as soon as possible. Make a list of everything you’ve fed them as well as the supplements you’ve given them. 

You also need to note the amount of supplements that you’ve given them. The frequency with which you have given them the supplements should also be noted.

For example, that you’ve dusted your leopard gecko’s feeder insects with calcium and vitamin D3 for every feed. 

By giving your vet a list of your leopard gecko’s food, etc., as well as how long you’ve noticed symptoms, they will be able to easier diagnose what is wrong with your gecko and whether it is, in fact, a vitamin D3 overdose. 

Do Leopard Geckos Need Vitamin D3 Supplements If They Have A UVB Light?

Can leopard geckos have too much D3?

Leopard geckos use UVB (ultraviolet) radiation from sunlight or a UVB light bulb to synthesize 7-dehydrocholesterol in the skin to form vitamin D3.

This is then used to absorb calcium and phosphorus in the body and is immensely important to form a strong skeleton, among other uses. 

If your leopard gecko doesn’t get enough D3 or calcium (or both) they can start suffering from an awful disease called metabolic bone disease (MBD) which slowly kills reptiles like leopard geckos horribly.

To ensure that this doesn’t happen, you should ensure that your leopard gecko always has access to enough vitamin D3 in the form of UVB light and supplements. 

The reason why we suggest using both a UVB light (to simulate sunlight) and a supplement, is because the UVB light bulb’s strength diminishes over the span of about 6 months.

This means that your leopard gecko will receive less UVB as time goes on. This is also why the bulbs need to be replaced so often. 

To ensure that your leopard gecko still gets enough vitamin D3 even though you’re using a UVB light, it’s better to dust the feeder insects with some calcium and D3 as well – but not for every meal.

How To Avoid Giving Your Leopard Gecko A Vitamin D3 Overdose 

The vitamin D3 that your leopard gecko makes in their skin is limited to the amount that they require and they have a type of “fail-safe” that keeps them from making too much vitamin D3 even if they decide to bask the whole day.

The extra vitamin D3 that is given in supplement form can therefore be a problem. 

Because it is possible to overdose your leopard gecko by giving them too much vitamin D3 as a supplement in their diet, you need to make sure that the vitamin D3 supplement you use doesn’t contain too much vitamin D3.

Vitamin D3 enriched calcium supplements are the easier way to give your leopard gecko enough calcium and vitamin D3.

The levels of D3 in these supplements range from about 20000 international units per kilogram to 400000 international units per kilogram. 

When giving your leopard gecko, give them a vitamin D3 supplement of 120 000 international units per kilogram or less (and keep reading to find out how often to use supplements).

Some of the best supplements to use – that contain these lower levels of vitamin D3 – are: 

How And When To Give Your Leopard Gecko A Vitamin D3 Supplement 

You should always give your leopard gecko some type of supplement with their food; either a calcium and vitamin D3 supplement or multivitamin.

However, don’t give them during the same feeding time as this may lead you to inadvertently give your leopard gecko too much calcium.

How often and how much you feed your leopard gecko will depend on their age and size:

  • baby and juvenile leopard geckos (under 1-year-old) should be fed every day 
  • adult leopard geckos (older than 1 year) should be fed every other day

How Much To Feed Your Leopard Gecko

how often do leopard geckos need d3?

A good rule of thumb is to feed your leopard gecko two appropriately sized insects for every inch of their body length.

So, if your leopard gecko’s body measures 3 inches from the snout to the base of their tail (don’t measure the tail as well), they need to be fed 6 insects that are no larger than the space between their eyes.

If their body measures 4 inches, 8 insects, etc. 

Getting The Feeder Insects Ready Before Feeding Your Leopard Gecko 

Before you feed your leopard gecko, you first need to make sure that their feeder insects are of the highest quality and contain the most nutrients possible.

This is done through “gut loading” the insects. Gut loading basically means feeding the insects lots of healthy food during the day or two before they’re dusted with supplements and fed to your leopard gecko. 

How To Dust Feeder Insects 

Dusting feeder insects after gut loading them is quite easy; you simply need to put them in a small container or bag that can close, add a little calcium and vitamin D3 powder or multivitamin powder, and lightly shake the container until all the insects are covered with the powder. 

Which Supplements To Include In Your Leopard Gecko’s Meals 

Tip: If you need a detailed guide on vitamins for leopard geckos plus a vitamin schedule and best supplements, simply read our leo vitamin guide here!

Baby and juvenile leopard geckos

For baby leopard geckos, you will need to dust every other meal with calcium with added vitamin D3 supplement powder. The other meals in-between can then be dusted with a multivitamin powder. 

Tip! Make a simple chart with the calendar so you can easily mark which days you’ve given calcium and vitamin D3 and which days only other vitamins. This will save you from worrying that you’ve given too much D3. 

Adult leopard geckos

For adult leopard geckos, you need to dust 2-3 meals per week with calcium and vitamin D3 powder.

The other 1 to 2 meals per week should contain gut-loaded feeder insects that have been dusted with multivitamin supplement powder. 

Although your leopard gecko needs access to calcium all the time to ensure that they get enough, it’s best not to give them calcium with vitamin D3 as the extra calcium in their tank if you’re using a UVB bulb.

This could easily lead to accidentally overdosing your leopard gecko with vitamin D3. Rather give them plain calcium only. 

However, should you not be using a UVB bulb, you can use calcium with vitamin D3 in their tank to “snack on” as needed.

We recommend giving shredded sepia bones instead. For more information on how to leave calcium powder in a leopard gecko tank, read this article.


Although it is possible to give your leopard gecko a vitamin D3 overdose by accident, it is quite easy to avoid this by not adding too much extra vitamin D3 supplements to their diet.

Just let them do most of the D3 synthesizing work by using a UVB bulb and ensuring that they have a new UVB light bulb at least once every six months. 

Pierre And The ReptileCraze Team
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