Does it matter how you take vitamin D? I get many letters about vitamin D absorption. “Should I take it with food?” “It is a fat soluble vitamin, so shouldn’t I take it with fat?” “Should I take it with a meal?” “Is it absorbed if I take it on an empty stomach?” The answer to these questions is generally that it does not matter. Vitamin D is passively absorbed in the lower part of the small intestine (the jejunum and ileum), at least in rats. Surprisingly, one study found that absorption with a very high fat diet decreased vitamin D absorption in rats by 30%. One human study of 25,000 IU as a single dose found that absorption was the same if scientists gave it with corn oil, whole milk, or fat free milk. Another study found that absorption of the powdered version was the same as vitamin D in oil. Another found vitamin D in oil was better than powdered but the difference between absorption rates was minuscule. The latest addition to absorption studies came out of Tufts University in Boston.
The authors, led by Dr. Sathit Niramitmahapanya, found that monounsaturated fats, like those found in beef and some oils, especially olive oil, was associated with better (that’s right better) absorption than vitamin D given with fish oils, but again the differences were not striking. Niramitmahapanya S, Harris SS, Dawson-Hughes B. Type of dietary fat is associated with the 25-hydroxyvitamin d3 increment in response to vitamin d supplementation. J Clin Endocrinol Metab. The fact is that the studies are so conflicting, and the 25(OH)D measurement techniques are so variable, that it simply does not matter if you take vitamin D in oil or as a powder, it does not matter if you take food with your vitamin D, or on an empty stomach. What matter is that you take enough so that you obtain vitamin D levels of 50 -60 ng/ml. This means you are no longer suffering from substrate starvation (your vitamin D system has all the vitamin D it needs for all of its many uses and is beginning to store some vitamin D for the future).
Remember, if you have trouble getting your doctor to order the test, or if your insurance does not pay for it, or if your co-pays and deductibles are too high, or if your doctor keeps saying 600 IU/day is enough, or if he says levels of 30 ng/ml is fine, the Vitamin D Council has an in-home vitamin D testing service. You can measure your vitamin D levels at home via finger prick test that requires a little blood on a blotter paper. See our “Testing for vitamin D” page to find out more about the in-home vitamin D test. Take Vitamin D With Largest Meal Absorption Increases by 50% When Vitamin D Is Taken with Biggest Meal, Study Finds May 7, 2010 -- Taking your vitamin D supplement with the largest meal of the day may boost its absorption substantially, according to a new study. Researchers from the Cleveland Clinic instructed 17 men and women, average age 64, whose blood levels of vitamin D were borderline insufficient despite taking supplements, to take their supplements with the largest meal of the day.
After two or three months, the study participants had about a 50% increase in blood levels of the vitamin, regardless of the dose they took. Researchers Guy B. Mulligan, MD, and Angelo Licata, MD, had noticed that patients typically report taking the supplement either on an empty stomach or with a light meal. Because the vitamin is fat-soluble, the researchers speculated that taking it with a big meal would improve absorption. Vitamin D is crucial not only to maintain bone strength, but research now suggests it plays a role in immune system problems, cancer, and cardiovascular disease. The researchers measured blood levels of the vitamin at the start of the study and two or three months later. Participants took a range of doses, and the researchers divided them into three groups: less than 50,000 IU a week, 50,000 IU, and more than 50,000 IU. The daily doses ranged from 1,000 IU to 50,000 IU. A dose of 400 IU is termed adequate for people 51-70, and 600 IU for people 71 and older, as set by the Institute of Medicine, but some experts believe much more is needed, especially in older adults.
The current upper tolerable level is set at 2,000 IU daily. The recommendations are under review and an update is expected this month. At the study start, the average blood level of the form of vitamin D measured, 25(OH)D, was 30.5 nanograms per milliliter. By the end, it was 47.2 ng/mL. A level of 15 and higher is termed adequate by the Institute of Medicine for healthy people, but the study participants had a range of health problems, such as osteoporosis and thyroid problems. Few foods contain vitamin D naturally, and some foods are fortified with it. Vitamin D synthesis is also triggered when the body is exposed to sunlight. The research is published in the Journal of Bone and Mineral Research.Vitamin D is crucial to bone health and also helps to regulate your immune system. Your body normally makes vitamin D by synthesizing sunlight through specialized cells in your skin. Individuals who live in northern climates do not get as much sunlight and may need to take supplements to get enough vitamin D. Vitamin D supplements can cause stomach upset in some individuals.
Additionally, taking more than the tolerable upper intake can also cause stomach cramping. Take your supplement with food. Taking a supplement on an empty stomach increases your chance of stomach upset.The National Institutes of Health recommends no more than 1,000 IU daily for children under age 12 and 2,000 IU daily for individuals over age 12. If you are taking close to this amount, reduce your dosage to the recommended minimum – 200 IU for adults under 50 and children, 400 IU for adults ages 51 to 70, and 600 IU for adults over 70. Increase your intake of foods that contain vitamin D to offset the reduced supplement amounts. Naturally occurring vitamin D will be less likely to cause a stomach ache. Food sources include fatty fish such as salmon or tuna; eggs, and foods fortified with vitamin D, such as milk. Gradually increase the dose by 100 IU each week until you reach the maximum or experience stomach upset. A gradual increase allows your stomach to adjust to the vitamin D and may prevent stomach upset.
Stop taking vitamin D and consult your physician immediately if you experience severe stomach pain, excessive thirst and a metal taste in your mouth. Those symptoms, in addition to bone pain and muscle problems, could indicate toxicity. Negative Side Effects of Taking Vitamin D Supplements Foods That Will Heal the Pancreas Can Vitamin D Cause Stomach Cramps? Herbal Tea for the Pancreas Side Effects of Taking Collagen Supplements A List of Foods That You Can Eat with Gastritis High-Protein Diet and the Pancreas The Best Vitamins for a Sensitive Stomach Stomach Problems & Low Vitamin D The Side Effects on the Stomach of Calcium & Vitamin D A Post Pancreatitis Diet Vitamin D & Heartburn Can a Vitamin D Supplement Cause Cramping and Diarrhea? How to Avoid an Upset Stomach from Multi Vitamins Which Types of Hard Alcohol Have No Sugars or Carbs? Can You Eat Potatoes With Pancreatitis? What Foods to Eat for an Inflamed Stomach Lining