How to Actually Take Vitamin D So That It Works

By Tina Chagoury, Clinical Dietitian · 5 min read · 2026-11-09

Most women taking vitamin D are taking it in a way that substantially reduces how much they absorb.

Vitamin D is one of the most commonly supplemented nutrients and one of the most commonly supplemented badly.

Take it with your main meal

This is the single most important practical point.

Vitamin D is fat soluble. Absorption improves substantially when it is taken alongside a meal containing fat, and it is considerably poorer on an empty stomach.

Taking it with your largest meal of the day is the simplest rule, and for many women it is the difference between a supplement that moves their levels and one that does not.

I have seen this repeatedly. A woman on a reasonable dose whose levels are not improving, taking it first thing with water. Move it to the main meal, retest, and the number moves.

Why K2 accompanies it

Vitamin D increases calcium absorption from the gut. Vitamin K2 is involved in directing that calcium into bone rather than allowing it to deposit in soft tissue.

This is why the two are so often given together as D3 with K2, and it becomes more relevant at higher doses and over longer periods.

Dose depends on your actual level

I am not going to give a universal number, because there is not one, and the correct dose depends on where you are starting from.

What I will say is that someone who is genuinely deficient may need substantially more than the amounts found in a general multivitamin, sometimes in the region of 5,000 international units daily to restore levels, and some protocols use a larger weekly dose instead.

That decision should be based on a test result and guided by your clinician, not on a guess.

Why you cannot eat your way there

This is the question I always get: can I just eat more eggs and salmon?

Let us do the arithmetic. One egg contains roughly 40 international units. Five eggs gets you to about 200. A salmon fillet contains between 400 and 600 depending on type and weight. Two fillets, about 1,000.

Now compare that to the amounts needed to correct a genuine deficiency. You can see the problem.

Vitamin D was never designed to come primarily from food. Your skin is the production facility, sunlight runs it, and food supports the process. Food is support, not the solution.

Why deficiency is so common even in sunny countries

Because your skin responds to UVB specifically, and UVB has to reach your skin directly. Not through a car window, not through the glass at home, not through an office window. Glass blocks it almost completely.

Consider how most people in the Gulf live: leaving home before peak UVB hours to avoid the heat, indoors most of the day, exercising in air conditioned gyms, covered or in shade when outside because it is fifty two degrees. Add sunscreen, skin pigmentation, age and body composition.

The sun is everywhere. The UVB is not reaching you.

What blocks it even when you supplement

• Elevated body fat, because vitamin D is fat soluble and gets sequestered
• Older age, reducing skin synthesis
• Gut malabsorption
• Chronic inflammation
• Certain medications

If your levels will not move despite adequate dosing taken with food, these are worth investigating.

The rule I never break

I never assume vitamin D status from geography. I test, every single time, and I retest after supplementing so we know whether it worked.

This article is nutrition education, not medical advice. Dosing should be guided by your own test results and your doctor.

Tina Chagoury is a licensed clinical dietitian based in Dubai, specialising in women's hormonal health and nutrient status, and the creator of the Hormone Reset Method™. Learn more and start here.