Vitamin D sources and proper sunlight exposure

sunlight is the best source of vitamin

Vitamin D is an essential part of a healthy diet, Consequently, all health professionals recommend that you get enough of it. Generally speaking, it is the easiest nutrient to acquire. proper Sunlight exposure is a great vitamin D source. All you have to do is sit in the sun for 30 mins, easy right? Not quite, 1 in 7 people have either vitamin D insufficiency or deficiency (basically you are not getting enough of it). That is despite, having easy access to a vitamin D sources. This is a shockingly high number.

If by any chance you decided to bask in the sun like a lizard after hearing that, let me dissuade you from that. It’s definitely a bad idea. Too much sun is a bad thing. I will explain why later.

What are the uses of Vitamin D?

It has a plethora of functions in the body, but they can be grouped into the following four:

  • Promoting healthy bones and teeth
  • Regulating insulin levels and supporting diabetes management
  • Supporting lung function and cardiovascular health
  • Supporting immune health

Additionally, in relation to its immune function, adequate vitamin D is a protective factor against severe Covid-19 infection.

Despite its health benefits and the availability of cheap sources of vitamin D, around 1 billion people worldwide are deficient.

Daily Requirement

So how much do you need? Assuming that you have no skin production of vitamin D because of inadequate sun exposure 600 IU/day is sufficient.

The daily requirements varies among the various age groups as you can surmise from the table below

 vitamin d requirement per age
Conversion: 1 µg = 40 IU. RDA=required daily amount
Adopted from Wikipedia


The main and the cheapest sources of Vitamin D is exposure to sunlight. Wearing an outfit that exposes the arms plus legs and getting exposed to the sun for 10-30 minutes, three times per week during the summer, should be enough

Moderate sun exposure that is less than the time required to burn the arms, shoulders, trunk, and legs should be sought. Once that limited time is achieved, it’s better to cover the skin or seek shade. Over doing (over exposure) it chronically has been implicated in the development of skin cancer.

Proper sunlight exposure

In relation to proper sunlight exposure be sure to keep these principles in mind.

  • Darker skin requires more minutes of exposure in contrast to lighter skin
  • Vit D synthesis is dependent on light intensity so midday sun is a better source than morning sunlight
  • Our skin makes it so the more skin we expose to sunlight the merrier
  • Exposure to light through the windows is insufficient because glass almost completely blocks UV-B light
  • Vitamin D toxicity is rare and is not caused by sunlight overexposure rather occurs from high doses of supplement pills
  • The further away you go from the equator the more sunlight exposure is needed. In extremes of the hemisphere earth’s ozone layer absorbs UV-B rays reducing our production
  • Using lotion and other certain skin products decreases exposure. For instance, sunscreen with protective factor 8 prevents as much as 95% of UV-B from reaching the skin.

Food Sources of Vitamin D

In case, getting adequate sunlight exposure is not feasible for you, consuming Vit D foods may be the only way to fulfill your daily requirement But dietary intake is highly dependent on nutritional habits and the country’s fortification strategy. Keep in mind that some countries provided better fortification and some even mandate to do so. The very few natural, non-fortified products which serve as a good source are:

  • Fatty fish like sardines
  • Diary products and
  • Cod liver oil…etc
Alternatives  to sunlight

Cod liver oil has 450 IU per teaspoon thus it covers 75% and 100% of the daily requirement of adults and kids respectively. This makes it the best alternative vitamin D source.

vitamin d sources
Adopted from Wikipedia


Some of our sources of vitamin D come from our diet but we should not ignore the natural capacity that we possess to produce our own from UV-B (sunlight). When using sunlight as a source of vitamin D we should do it in a proper way to benefit from it and avoid its harm. Don’t forget to workout.

If you are interested in additional reading, check out the sources below


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