When it comes to vitamin D, nearly everyone in the US is deficient.
Because 90% of the US adult population is believed to be vitamin D deficient, it’s safe to say that the majority of dogs are too.
Below I’ll share with you the steps you can take and the foods you can feed to ensure that your dog is getting healthy amounts of vitamin D.
What Is Vitamin D?
Vitamin D is a fat-soluble vitamin that’s stored in the liver and fatty tissues.
Vitamin D is somewhat different than other vitamins because your dog’s body makes most of its vitamin D on its own, rather than solely relying on food sources.
The process is achieved by converting sunshine into chemicals that are used by the body.
Interesting Vitamin D facts:
- When UV-B sunshine rays land on your dog’s skin, a substance in the skin called 7-dehydrocholesterol is literally converted into vitamin D3.
- Vitamin D actually becomes a hormone within your dog’s body.
- Vitamin D is really a precursor to a steroid hormone.
- Studies show that vitamin D impacts not only the body’s skeletal structure but also blood pressure, immunity, mood, brain function and ability to protect itself from cancer.
What Causes Vitamin D Deficiency in Dogs
Years ago dogs spent more time outdoors, both because more dogs were “outside dogs” and because we spent more time outside so naturally, so did our dogs.
With all the time we and our dogs now spend indoors, it’s no wonder vitamin D deficiency affects over a billion people worldwide and the majority of pets.
So, what are the risks of vitamin D deficiency in dogs?
Vitamin D deficiency is correlated with increased risks of developing the following:
- autoimmune diseases
- common cancers
- diabetes
- heart disease
- hypertension
- infectious diseases
Vitamin D Deficiency Symptoms
Dogs with vitamin D deficiency are at an increased risk of developing health complications and conditions like cardiovascular disease, various types of cancer and immune disorders.
Vitamin D deficiency symptoms can be linked to the following health problems:
- anxiety
- arthritis
- asthma
- autoimmune diseases
- cancer
- chronic fatigue
- chronic pain
- depression
- diabetes
- heart disease
- high blood pressure
- inflammation
- swelling
- insomnia
- weak or broken bones
- weakened immune system
- weakness
Top 6 Health Benefits of Vitamin D for Dogs
Vitamin D Contributes to Bone Health: Vitamin D plays a role in calcium absorption into the bones. Calcitriol (converted vitamin D) works with the parathyroid hormone to maintain calcium levels. A deficiency in vitamin D can result in the softening of your dog’s bones. Additionally, a deficiency increases your dog’s risk of experiencing fractures or broken bones.
Vitamin D Protects Against Cancer: It has been found that vitamin D plays a role in preventing tumor growth and cell differentiation. Researchers have found that increased sunlight exposure and circulating levels of vitamin D are associated with the death of many types of cancer.
Vitamin D Combats Heart Disease: Animal studies have found that the disruption of vitamin D signaling promotes hypertension, atherosclerosis and cardiac hypertrophy.
Immune System Support: Your dog’s immune cells contain receptors for vitamin D, and it’s been found that vitamin D prevents excessive inflammatory responses – the root of many chronic diseases and autoimmune disorders: arthritis, irritable bowel syndrome, etc.
Supports Hormone Regulation and Helps Improve Mood: Vitamin D deficiency has been linked to an increased risk for mood disorders, including depression, seasonal affective disorder, and severe mood problems.
Supports Concentration, Learning and Memory: Several studies have shown that vitamin D affects our ability to make decisions, concentrate and retain information. If we experience these negative effects we can be sure our dogs do too.
Luckily, there are ways you can naturally increase your dog’s vitamin D levels and decrease your dog’s risk of developing the above health conditions.
Letting your dog spend quality time in the sun, is the surest way to make sure your dog is getting enough vitamin D. Eating vitamin D-rich foods also helps improve your dog’s blood levels.
How Much Sun Is Enough for Vitamin D for Dogs
Most experts recommend that people get about 10 to 15 minutes of direct sunlight daily, which is arguably not enough. Additionally, your dog’s skin is covered by hair. In order for them to get enough sun, they need to spend a good amount of time outdoors. Depending on the time of day, 1-2 hours is ideal.
Time of Day is Important
You want to look at your (or your dog’s) shadow and see that it’s shorter than you (they) are. This tells you that the sun is high enough in the sky to be strong enough to convert vitamin D in your dog’s skin.
This will generally happen during the hours of 10AM to 3PM when the sun is high. When the sun is lower it is less likely to penetrate your dog’s skin effectively.
Why Plant Matter is Not a Healthy Source of Vitamin D for Dogs
Before we talk about the top four food sources for vitamin D for dogs, let’s first talk about what you shouldn’t feed.
The vitamin D needs of our dogs is yet another reason why feeding plant matter for a “balanced” diet is not healthy. Of course, there are many reasons why feeding carnivores plants is damaging their health, so here are more for you to read up on.
There are two types of vitamin D:
- vitamin D2 (ergocalciferol)
- vitamin D3 (cholecalciferol)
The precursor to vitamin D is found in both plant and animal products, but animal-derived products of vitamin D3 are more absorbable and beneficial.
Why? Vitamin D is made by the body in one of two ways:
- Vitamin D2 is created by irradiating yeast and other molds (known as vegetarian vitamin D2)
- Vitamin D3 is created by irradiating animal oils and cholesterol
Our human bodies are able to covert some D2 to be used for body functions but prefer and are able to use vitamin D3 much more effectively.
This means that carnivores, who are designed to utilize animal-derived foods and not plant matter, are likely unable to use D2 at all.
D3 from animal products is closest to what sunlight naturally produces in the body when the skin converts UV light. Vitamin D3 has been shown to convert up to 500 times faster than D2 and has been estimated to be four times more effective in humans.
Foods High in Vitamin D for Dogs
- Salmon
The USDA states that one 3.5-ounce (100-gram) serving of salmon has between 361 and 685 IU of vitamin D.
However, keep in mind that these numbers may be for farmed salmon since sourcing wasn’t specified.
On average, wild-caught salmon has 988 IU of vitamin D per 3.5-ounce (100-gram). Some studies have found even higher levels in wild salmon — up to 1,300 IU per serving.
Additional Study of Vitamin D Levels in Wild-Caught Salmon
As always, there are greater nutritional benefits in wild and pasture-raised animal products.
- Herring and Sardines
Fresh Atlantic herring has 1,628 IU per 3.5-ounce (100-gram) serving.
Other types of fatty fish are also good vitamin D sources. Halibut and mackerel have 600 and 360 IU per serving.
However, because of the high levels of chemicals found in bigger fish, it’s always best to feed smaller (the smaller the better) fish to your raw fed dog.
- Cod Liver Oil
If you’re trying to correct a vitamin D deficiency in your dog, cod liver oil an excellent temporary source of vitamin D — at about 450 IU per teaspoon (4.9 ml).
Cod liver oil has been used for many years to prevent and treat vitamin D deficiency in children.
Keep in mind that cod liver oil has quite a lot of vitamin A in it (90% of the RDI in just one teaspoon) and vitamin A can be toxic in high amounts, so make sure you don’t give your dog too much.
- Egg Yolks
Most of the protein in an egg is found in the white, but the fat, vitamins and minerals are found mostly in the yolk.
While one egg yolk from commercially-raised chickens has 18–39 IU of vitamin D (not high at all), chickens raised outdoors, on pastures, where they can run, play and lay in the sun, lay eggs with up to 6,000 IU of vitamin D per yolk.
That’s a huge difference! Quality is key.
“Common” Foods that Have Vitamin D for Dogs Fed a Raw Diet
Because common animal-derived foods for raw fed dogs (beef, pork, chicken, lamb, rabbit, etc.) don’t have a lot of vitamin D, foods aren’t the only source you should rely on. While any animal-derived foods from grass-fed animals are going to have much higher levels of any vitamin or mineral, nothing quite compares to the four foods above and quality time outside in the sun.
Vitamin D Interactions and Concerns
Your dog’s skin is able to regulate vitamin D conversion. It can store pre-vitamin D for future use and destroy amounts beyond what is safe for the body to store.
So, toxicity is rare and deficiency is usually a much bigger concern.
Keep in mind that because vitamin D is a fat-soluble vitamin, it ideally needs to be consumed with fat for optimal absorption.