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I created this website so you would know
- why you need vitamin D3
- how best to take it.
It's a long story, but this is the short version:
Vitamin D3 will increase your quality-of-life and life-expectancy.
Best way to get D3? Sunlight, nature's own prescription.
But if we avoid the sun, we still have two choices:
- supplement an effective dose, or
- remain vitamin D-deficient.
Choose wisely!
Alex St Clair
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This page contains...
Two main Vitamin D sources - sunlight and food
Vitamin D from vegetable sources
Vitamin D from animal sources
Cod liver oil
Avoiding vitamin D2
Vitamin D3 from sunlight
Maximise vitamin D3 with safe sun practices
Getting enough vitamin D all year round
Vitamin D3 Capsules (5000 IU)
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Vitamin D Sources
Natural sources of vitamin D
In nature, your body has only two vitamin D sources: sunlight-on-skin, and food.
When our ancestors were living in Africa, sunlight-on-skin was a lot more important for their vitamin D levels than was food. For most of us today, that is still the case.
But the further away from the equator they lived, the less UV-B sunlight was available to their skin, especially during winter. So food became an important secondary source of vitamin D, to tide them over the colder months.
We'll return to sunlight, but for now let's look at food sources of vitamin D.
Natural sources of vitamin D
Food sources can be either vegetable or animal.
On the vegetable side, algae, some bacteria and certain funguses (i.e. mushrooms) produce small amounts of a vitamin D precursor which we call vitamin D2 (or Ergocalciferol).
Quite small amounts may occur naturally in our diet. We can use it, but as we shall see, it's not the ideal form for us.
Fortified foods provide some vitamin D to the average first-world diet, mainly from milk (100 IU per cup), margarine (60 IU per tbs) and some orange juice and breakfast cereals, but not nearly enough to prevent vitamin D deficiency.
Also, in practice, the level of fortification in foods is quite erratic.
Vitamin D foods
Animals use vitamin D just as we do, and we can obtain it from them, in the form of vitamin D3. Main sources are shown below:
| Animal Sources of Vitamin D3 | ||
|---|---|---|
| Source | Serving | IU's |
| Salmon | 3 oz | 300 |
| Mackerel | 3 oz | 290 |
| Sardines | 2 oz | 285 |
| Tuna | 3 oz | 200 |
| Egg yolk | 1 yolk | 20 |
| Liver (beef) | 3 oz | 13 |
| Milk | 1 cup | 12 |
| Cheese | 1 oz | 12 |
| Cod liver oil | 1 tsp | 500 |
This table shows average values. Actual values can vary widely, naturally.
As you see, it is possible to obtain meaningful amounts of natural vitamin D3 from our diet, but only if we eat a lot of fish!
These days, because of the pollution of our oceans (PCBs and heavy metals), we need to be careful where our fish is caught.
Total vitamin D intake from food is probably less than 200 IU for the average person.
Cod liver oil as a source of vitamin D3
Cod liver oil (only one or two teaspoons a day for an adult) can be used to provide some vitamin D3.
It must be a high-quality, natural cod liver oil, with its full complement of natural vitamin A and D, which means that each teaspoon should contain about 5000 IU of vitamin A, and 500 IU of vitamin D.
If you were to exceed 2 teaspoons a day, the vitamin A would become toxic before the vitamin D (but only after you had drunk a great deal of oil!).
Some cod liver oils are processed to remove the natural vitamins. Then after processing, synthetic vitamin A and vitamin D2 are added back into the oil. The natural proportions of vitamin A to vitamin D may also be changed in such oils. These processed oils are best avoided.
Cod liver oil seems like a great way to get your omega-3 fatty acids at the same time as your A and D vitamins, but in fact you cannot get enough vitamin D from natural cod liver oil alone without getting an overdose of vitamin A.
Also, vitamin A competes in the body with vitamin D, so if you are trying to raise your vitamin D levels, taking extra vitamin A is a bad idea.
Avoiding vitamin D2
Vitamin D2 has been used to fortify certain food products, milk for instance, but it added a detectable bitter flavour to the milk, so milk fortification now uses vitamin D3.
You still find vitamin D2 today in some fortified foods, and in some vitamin D supplements. Many of the vitamin D supplements produced by pharmaceutical companies (for prescription by doctors) contain vitamin D2.
Since vitamin D2 has been found to be less effective at raising blood levels of Calcidiol (the storage form of vitamin D), and creates undesirable by-products when metabolized, most knowledgeable doctors now recommend vitamin D3 (cholecalciferol) to their patients.
Some multivitamin products, particularly low-cost formulations, also use vitamin D2 (ergocalciferol) instead of vitamin D3. (If it just says vitamin D, or calciferol, it's probably D2.)
If you are going to be taking oral vitamin D supplements, you want to be sure they contain vitamin D3 (cholecalciferol).
But before deciding on supplementation, let's take a closer look at sunshine as a source of vitamin D3.
Vitamin D3 from sunshine
Nature intended that we should expose our skin to sunlight. That way, we would get all the vitamin D we needed from our built-in vitamin D3 factory.
Hunting, fishing, gathering fruits, vegetables and nuts would have kept us pretty well exposed, and well stocked-up with vitamin D.
Bear in mind, there might be other undiscovered benefits to having sunshine on our skin, besides getting enough vitamin D, so we should not be too eager to ignore what nature intended for us.
Finding enough sunshine
Living close to the equator, a few thousand years ago, modelling a stylish fig-leaf or loincloth, we would have needed only a few minutes in the sun during the summer, to get all the vitamin D we needed.
We could even store some away (in our fat tissue and muscles) for a rainy day.
In winter we could still get our entire vitamin D requirement - from sun exposure alone.
But as we get further from the equator, we have to choose our times more carefully.
At 50 degrees of latitude, we need to take our sun pretty close to midday during spring and autumn to make enough vitamin D.
In winter we'd have to make another plan altogether. There just isn't enough UV-B around. (Besides, it's too cold to expose skin!)
Safe sun practices to maximise vitamin D
Most of us can use the sun as our source for vitamin D, for at least part of the year, so here are some safety and effectiveness guidelines.
- Vitamin D production is naturally finished long before you start to burn, no matter what color your skin. (Obviously, that happens a lot quicker if your skin colour is very light.)
- A light-skinned Norwegian blond would take about 10 minutes of near full-body exposure in strong sun to create a good daily dose of vitamin D3.
- A dark-skinned African might take 90 minutes to make the same amount of vitamin D. You might be somewhere in-between, depending on your complexion.
- Set your own personal daily sunshine limit, in minutes. It should be no more than half the time it would take you to become the slightest bit sore from sunburn.
- Also, your daily limit should be less than the time it takes for you to notice any change in your skin colour. If you are unsure, start off slowly, but do start!
- When you get the opportunity, try to expose as much skin as possible (but not for longer than your daily limit). The more skin you expose, the more vitamin D you will make.
- But unless you are a lifeguard, it may be hard to get the sunlight your body requires to make enough vitamin D.
- At least four times a week of this kind of exposure is needed to get you into optimum vitamin D territory from sunlight alone. Older people need even more.
- You can't overdose on vitamin D through sun exposure, no matter how often you do it.
- Don't wear sunscreen all over while you are getting your vitamin D sunshine. An SPF 15 sunscreen absorbs 93% of the UV-B rays. What gets through isn't nearly enough.
- Don't sit behind glass. UV-B rays are 95% absorbed by ordinary window glass and 99% absorbed by your car windscreen.
- Avoid exposure to your face and neck. (Keep those youthful looks as long as you can!) Sunscreen-on-face is an easy way to protect it, or wear a hat. Large-framed sunglasses help to protect the delicate area around the eyes. You may want to put sunscreen on your hands, too.
- If you are exposing more skin than usual, take particular care of the newly-exposed parts. They will burn quicker because they are as yet untanned.
- Every few minutes, turn to expose a different part.
- When your time-limit is up, retire inside again, cover up, or put sunscreen on all exposed areas.
- When on holiday in a warmer climate than usual, start off with much shorter exposure times than you would use at home. Hotter sun burns quicker.
- Some Vitamin D3 is created inside your skin cells. That won't wash off. But more is created in the natural skin oil on top of your skin. This can be washed off, especially if you use soap.
- So after sunning, use soap only where you need it. Most of the body is cleaned well enough when bathed with just water. Water bathing (not too hot!) allows skin oils to remain on the skin. Then your skin absorbs the oil (over about 24 hours) and the vitamin D with it.
- Remember - sun is dangerous. The same UV-B light that creates your vitamin D3 can also damage and age your skin. Never allow yourself to burn, even slightly. Don't even turn pink! It is not necessary.
- Children also need sun exposure to build up healthy vitamin D levels, but will need adult guidance.
- Prepare your body for sun exposure by taking antioxidants. Fresh fruits and berries are great. A daily antioxidant supplement is a good idea too.
- For protection from UVB damage, there is a natural antioxidant herb with a special affinity for skin, called polypodium leucotomos. It's a kind of fern. After taking a course of this antioxidant, you may find you can stay in the sun more than twice as long without burning. But this doesn't help you make more vitamin D.
These suggestions apply to healthy, undamaged skin. Avoid exposing areas of your skin which are already sun-damaged. If this makes it impractical to sunbathe, then rather take vitamin D3 supplements. (The same applies if you've already had a skin-cancer.)
Vitamin D3 -All year round
Depending on where you live, you may be able to use sunlight as your primary source of vitamin D for several months of each year. I believe this is the best solution for getting some, if not all, of your vitamin D requirement during the warmer months - if this is practical for you.
For the rest of the year, don't allow your vitamin D levels to dive. Best health is obtained by maintaining your 25(OH)D blood level at close to optimum, all year round.
During the winter months, take a good quality vitamin D3 supplement. First see Vitamin D Dosage.
Tanning Beds and Sunlamps
One last alternative, for people with deep pockets - you can use a safe tanning bed to provide UV-B to your skin all year round, in precisely controlled doses. What bliss! (Cover sensitive parts!).
UV lamps are also available to do the same thing.
The equipment has to provide exactly the right wavelengths of UV light, in the right proportions, in order to be safe. Buy from a reputable manufacturer, and use strictly in accordance with their instructions.
