Reinforce Your Sleep with Vitamin D  

By Christina Reiter, BSN, CCN

It is estimated that over half of the world’s population is vitamin D deficient.

At the same time, it is well known that sleep disorders are fast becoming an epidemic. Many studies have shown a link between low vitamin D and decreased melatonin production, which affects sleep quality and other common conditions.

Most people are deficient due to lifestyle: they work indoors, most under fluorescent lighting, with few (if any) windows and the A/C cranked; wear clothing, and when outdoors, use sunscreen to help prevent certain types of skin damage. These are the accepted realities of modern life, yet they also take away from natural vitamin D production.

Why not simply go outside and get some sun to boost vitamin D levels? The notion that humans somehow “soak up” vitamin D from the sun is false; Rather, it is the interaction of ultraviolet (UVB) light with a cholesterol derivative found in the skin and other factors (such as time of year, sun angle, distance from the equator, latitudes and amount of cloud cover) which causes D to be formed. The additional variables make it challenging for humans to produce sufficient vitamin D levels to maintain healthy levels.

While many dream of quitting their jobs and relocating to a small island off of Florida, this is an unrealistic solution for most working Americans. Regardless of sun exposure, therapeutic levels of vitamin D can only be achieved and maintained through supplementation. Simply taking large doses of vitamin D is not the answer for preventing vitamin D deficiency. Too much or too little can also have side effects, including reducing the quality of your sleep.

According to the Vitamin D Council, Americans need 1000i.u. for every 25 pounds of weight, although using a blood test is the best way to know your ideal dose. A healthy human body uses anywhere from about 3000 to 5000i.u. of vitamin D per day through various metabolic pathways.

Keep in mind that these amounts are adjusted according to your age, weight, absorption, skin color and normal sun exposure. Therefore, if you are outside with adequate sun exposure, such as at sporting events, summer camp and through landscaping, try not to use a heavy sunscreen; rather do wear a long-sleeved, light-colored shirt and/or a hat and leave the vitamin D supplements at home: more is not always better. Too much vitamin D can cause headaches, hair loss and inflammation in the body. The United States government recommends no more than 4,000i.u. per day and other authorities argue that no more than 10, taken per day. (Note: 10,000i.u. is also the amount produced after a day’s worth of maximum sun exposure.)

When is the Best Time to take vitamin D?

Vitamin D is inversely related to melatonin, your sleep hormone; therefore, if you take it with dinner or around bedtime, there is a good chance the quality of your sleep may be negatively affected. For this reason, take it early in the day with breakfast or lunch, as digestion with a small amount of fat. Even a trivial amount of fat in a meal (or in a softgel) allows vitamin D to combine with other fatty acids and, later, with enzymes to promote complete breakdown and absorption into the liver and kidney.

In one experiment researchers concluded that taking vitamin D in the morning is better than taking it at night. A morning dose of D correlated with increases in REM, deep sleep, and the number of hours asleep. When the dosing was reversed to where the D was taken at night, sleep quality plummeted with significance.

With busier and busier schedules becoming the norm, healthy sleep is worth its weight in gold. Most authorities stress the importance of no less than 7 hours nightly, on average, for each adult. Should your average sleep duration begin to lag as the workweek comes to a close, take extra vitamin D with breakfast and focus on turning in earlier. If you are not practicing good sleep hygiene and not taking adequate vitamin D at the right time, you are setting yourself up for a triple fail. Practice all three and these habits will reinforce and amplify the effect of the other.

If you are unsure of where to start, there are a few options. Your first stop may be to visit your doctor and find out with a simple blood test where your vitamin D levels are right now (Ideal ranges anywhere from 30-110ng/mL). Remember: D levels are influenced by time of day, time of year and supplementation. If you have a vitamin D level that is more than six months old, it is time to do it again. If your insurance will not cover another test, there are cash-pay and discounted options through alternative laboratories (i.e. lab testing services) and other locally owned and operated lab service providers, as recommended by your pharmacist.

Once you have your results in hand, come visit for more personalized recommendations regarding which vitamin D is the best for you.

Book your appointment today with me, Christina, a certified clinical nutritionist, to review your medications, supplements, laboratory results and dietary habits.


You may also visit with Donna S. Barsky, Pharm.D. (Doctor of Pharmacy) / Owner. Donna is an active member of the American Academy of Anti-Aging Medicine, a Certified Diabetic Counselor, a Pharmaceutical Preceptor (trains pharmacists), a functional medicine expert and compounding “guru.”