Food Sources of vitamin D3

Vitamin D is one of the oldest hormones we know of. Plants and fungi make vitamin D2 , also called Ergocalciferol. It is similar to our vitamin D and probably older but it is not what we make on our skin! We make D3, Cholecalciferol. In fact, insects, fish, birds, reptiles and mammals all make D3! Animals that are nocturnal, that  go out only at night and are never exposed to the sun, still need vitamin D. In order to be nocturnal their bodies must be completely OK with using the vitamin D2 they get from plants.  Rats and mice can use D2, and D2 was the first vitamin D that was discovered.  Animals that are nocturnal predators  rely on the D3 made and stored by the animals that they kill and eat. When we ate the entire animal raw we also benefited from this source, but now that we eat cooked meat we get very little D3 from food. For most of us who are awake in the day and sleep at night the D has always been made on our skin, from the sun. When I first started suggesting vitamin D to my patients, and didn’t know any better, I gave prescription strength D2 once a week because that is what is still “recommended” in the medical literature. But I soon found out that 9/10 of the patients I gave it to didn’t like it, their sleep was worse, they had more belly complaints and more pain. My other patients taking D3 were doing better. Finally I read the articles describing that these are definitely not the same chemical, they are absolutely not equivalent, even in their bone effects.

Vitamin D does actually exist in our bodies as vitamin D3 25OH just as it is supplied in pill form. Most of this form is concentrated in the liver. Sea animals such as dolphins, who have no hair or scales but are habitually under water probably get some D3 made on their skin but also get D3 from the animals they eat. Dolphins and other predators eat the entire animal raw, which we rarely do now.  Aboriginal peoples such as the Inuit or Eskimo who had dark skin despite living at very high latitudes probably lived on the D3 they obtained from raw seal, whale or polar bear liver. The habitual eating of raw liver is one of the ways that humans were able inhabit areas where their skin color did not match the sun exposure. Therefore in some specific areas, changes in the diet have definitely contributed to vitamin D deficiency.

Cod Liver Oil:

Be wary of taking vitamin D in the form of cod liver oil. It was the first supplemental source, and you’ll notice the word liver in there. But if you are trying to use vitamin D to make your sleep perfect in order to heal your body you’re doing something a little different than “living a natural life”. Cod liver oil cannot guarantee the dose of vitamin D in each serving because it varies from fish to fish and bottle to bottle. There is so much that is still unknown about vitamin D and getting the D blood level to be stable over time is so difficult, that easy access to cheap consistently dosed pills is one of the few advantages we have today. So use the pills instead so you know exactly what dose you are taking every day.

Vitamin D and Skin Cancer

Sun exposure signals the deeper layers of the skin to make melanin. Melanin is then sent up to the surface layers of the skin to protect us, like a little black umbrella. Melanin makes us darker and blocks production of vitamin D in the skin. As the summer wears on, if we slowly get more and more exposure, we become darker in color and make less vitamin D per hour. People who live in countries closer to the equator in Africa or Central America who still live outside stay tanned all year long. The skin is designed to have a connection between the blood level of D25OH and the amount made in the skin. A person with normal melanin, who is still living outdoors or using a tanning bed daily is not able to produce a vitamin D blood level over 80 ng/ml by sun exposure alone, so that appears to be the normal biological upper level.

This does not mean that liberal sun exposure is good for everyone! There are people who have very little or no melanin in their skin. They have specific genetic mutations that became common in parts of the world such as Scotland and the Nordic countries where there are very few months of UVB light in summer and very few clear days for sun exposure. Losing the melanin was a survival advantage, we all need Vitamin D to survive so in low sun environments people with red hair and very white skin survived better than their dark skinned cousins. The people who are not able to make melanin cannot tan and are therefore at risk for severe sunburn, skin damage and skin cancer. People with this skin type, once transplanted to a very sunny environment must use sunscreen or clothing to protect their skin. But people of color who possess their own sun screen only need to protect their skin when they are first exposed in summer. They can still burn if they’re not careful, but each person, with experience, begins to know how much sun they can tolerate without producing a sunburn. It is not sun exposure that makes skin cancer, it is the damage of sunburn and the lack of vitamin D in the skin to repair the DNA damage that leads to skin cancer. Vitamin D enters the nucleus of skin cells and repairs the DNA damage. Squamous cell carcinoma grown in a petri dish becomes a normal cell when exposed to vitamin D!

People who are very dark skinned came from very high sun environments at the equator. Their bodies were made to be able to live outside all day long and be healthy and make enough D to live long and prosper. They will need more sun exposure to make the same amount of D as a lighter skinned person. Dark skinned people did not start to have skin cancers until the last thirty years. This means that the cause and the treatment are the same and like everything else in nature, there’s a balance. Don’t burn your skin is still good advice. Use your judgement and your own experience with your body!

One other warning: Skin cancer is related to damage over time. If I’ve had low vitamin D for the last thirty years of my life it means that the DNA damage done to my skin over that span of time was NOT repaired because there was no vitamin D on the skin to repair it. That means that the state of my skin at the time I start increasing my sun exposure plays a role. Start doing intelligent sun exposure with your kids but if you already have obvious sun induced skin changes you should use sun screen and do the D supplementation orally. I suspect that once a skin cell has turned fully cancerous, vitamin D supplementation does not turn it around the way it does in the petri dish. Since we have easy, cheap supplementation it’s better to be safe if you’re over 40, even if you have dark skin.

Sun Exposure is the Natural Way to Make Vitamin D

We are one of the few animals on earth without feathers, scales or fur. It turns out to be a bit risky not to have a covering on the skin, but there may be some advantages to being hairless. Though we don’t have fur to block the sun we are able to make a portable, temporary sunscreen that allows us to protect our skin from the sun when we need to. All animals on the planet, as far back as insects, fish and reptiles use their skin to make vitamin D, and so do we. We make vitamin D from the UVB rays of the sun as they hit our skin, but only outside and with direct sun exposure. UVB is the only wavelength of light that changes 25 dehydroxycholesterol in our skin to a “pre” vitamin D, the chemical that then becomes vitamin D25 OH.  The clothing that we wear and the sunscreen that we put on both block the UVB rays. They also block the production of vitamin D on the skin! Because the D in most food supplements is vitamin D2, (D2 is what rats, nocturnal animals, use), the food supplementation that the US government has provided in milk does not replace the vitamin D3 made on the skin. (Most doctors do not know the difference, and the current Family Practice recommendations are still vitamin D2 50,000 IU once a week.)

How to use the melanin in your skin to your and your child’s advantage:

Human skin coloring is based on a chemical called melanin. Melanin is a chemical that is designed to absorb energy. In the skin it is used to absorb potentially damaging UVB light. High energy light rays of UVA and UVB frequency from the sun or from a tanning bed can damage the DNA in our skin cells. That damage, if not repaired, can lead to skin cancer. We hairless beings incorporated a wonderful, home-made sunscreen into the surface of our skin. We can make it on demand and adjust it in relation to our sun exposure. We also use the vitamin D on our skin to repair that same DNA damage. So… way, way before doctors or sunscreen ever existed, our bodies had this all worked out!

In summary: be smart, be careful, listen to your body. If you can make enough vitamin D in the summer to make you sleep all the way through the winter then you don’t need to supplement. The bad effects of vitamin D deficiency don’t happen in one season, they accumulate over years of sleeping badly and not repairing our body for years on end. In normal populations that lived away from the equator there was a normal yearly  change in the vitamin D blood level. It went up in the Fall and down again in the Spring. Probably, if the lowest Winter D level was 40 ng/ml the intestinal bacteria changed  enough for us to gain a little weight, then when the D went up again in summer the normal bacteria grew back and we would lose the extra pounds.



Vitamin D dosing is very personal:

Each person has their own personal dose of vitamin D that must be learned by testing the D blood level. An example: A mother is dosing three of her kids with 2,000 IU/day for one month in the winter, Nathan goes from 20 ng/ml to 50 ng/ml, Samantha goes from 18ng/ml to 25ng/ml and Alex goes from 25ng/ml to 95 ng/ml, each are taking exactly the same dose for same period of time.

The maximal amount of vitamin D made on the skin of a light skinned person, fully sun exposed, middle of the summer, is said to be 20,000 IU, so that is the largest dose that I will start even in someone whose level is very low (undetectable –10ng/ml). That does not mean that everyone gets into the right range with that dose, however. Some of my patients required much bigger doses, up to 50,000 IU (D3 not D2) per day for several years. They had usually been very sick for a very long time and we worked up to that dose over many months as their D level failed to increase on lower doses. Though it is documented that there are people who have specific problems with absorption, I have tried various types of replacement in those who needed larger doses: on the skin, sublingual etc, and I did not find that those methods were any more reliable than oral pills.

I disagree with the proposed idea that fat people have lower D blood levels because they’re fat. It has been suggested that they dilute their vitamin D by storing it in their fat, instead of their blood. Obese people may indeed have lower D levels, and require higher doses, but I think that is because they have been sick longer. Their low D level caused their obesity, not the reverse. 5-6 years of dosing the same obese person also revealed that the dose requirements fell over time, into a more routine range, even while the weight remained the same.

There are several other variables that affect vitamin D blood dosing. Based on my experience with over 5000 patients, about one in 50 people needs much smaller doses. These people operate in a dose range of 1/10th of what everyone else needs. (This probably suggests that they also make less vitamin D per sun exposure, though that has yet to be proven.) It is also impossible to predict who will need these smaller doses; they can have any initial D blood level, can be any color and any age. If you are one of these few you will feel terrible within a week of starting a D dose that is ten times too big, and this is one of the reasons I suggest that you start slowly.

I did not attempt to measure any of the genetic mutations that affect skin production of vitamin D, vitamin D binding protein, GI absorption, or the vitamin D receptor. These are all variables that do indeed exist and need to be sorted out once the “healthy” D level is actually agreed upon. Until then I don’t think it makes sense to blame all differences in D dosing and blood levels on “problems with absorption”. What I learned over time was that if the level wasn’t going up usually the dose being given was just too low. Please see the chapter on “Vitamin D Controversies” for more details.