Is there an optimal time of day to take vitamin D for maximum absorption? I was told it will do nothing for you if taken in the morning. It only does your body good if you take it with an evening meal that contains fat. Is this true? — D.H., San Francisco, CA

Dr. Micozzi: What you were told is half right. Vitamin D is best absorbed in your body when it’s taken with fat. But it doesn’t matter what time(s) of day or night you take it.

Vitamin D is a fat-soluble vitamin, meaning it’s stored in your tissues and then released when your body needs it. So the purpose of taking a daily vitamin D supplement is to maintain adequate, long-term stores of the vitamin in your body. That’s why it doesn’t matter what time of day you take it.

In contrast, water-soluble vitamins like B and C can’t be stored, so it’s important to take them regularly to ensure an optimal supply in your body at all times.

What does matter when it comes to vitamin D is how you take it. It’s important to take D with fats or oils, or else it can’t be absorbed from your gastrointestinal tract into your blood and tissues. That’s why many people take vitamin D with a meal that contains essential fats.

In fact, I hope you are getting some essential fats at every meal. If you are still eating a high-carb, high-sugar breakfast of fruit juice and cereal—or, even worse, muffins or pastries—then you will not absorb most of the vitamin D you take. But if you have a healthy breakfast that includes dairy or eggs, your daily dose of D will be easily absorbed. The same goes at every meal.

Of course, sometimes you can simply forget to take D while eating. That’s why the vitamin D3 formula I include in my Smart Science Nutritionals product line is in liquid form, “suspended” in oil.

(You can also get it combined with astaxanthin in my CoreXanthin formula. Astaxanthin is a powerful antioxidant in its own right, and has been shown in studies to help support metabolic, cardiovascular, and neurological health as well as a healthy inflammatory response.

You can take either of these formulas straight or add them to any beverage. To order Smart Science Liquid D3, click here or call 1-800-292-5808 and ask for order code EOV2S3AB. To order CoreXanthin, you can click here or call 1-800-292-5808 and ask for order EOV2S3AA.