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By UC San Diego Health Experts   |   May 01, 2017

​Our experts answer questions about when it’s appropriate to take vitamin D supplements, whether coconut oil is as healthy as people think, and whether there are minimally invasive ways to treat fibroid tumors.

  1. When is it appropriate to take Vitamin D?
  2. Coconut oil has become very popular in health food circles but is it really better than other oils? 
  3. What are some non-invasive ways of treating fibroid tumors?

When is it appropriate to take a vitamin D supplement?

Alia Al-Tamimi, registered dietitian, UC San Diego Health

Vitamin D, the “nutrient of the decade,” is a conditionally essential micronutrient that plays a vital role in our body. The classical function of this vitamin is to support a healthy bone mass. In addition, substantial scientific evidence has linked low levels of vitamin D to an increased risk of cardiovascular diseases, cancer, diabetes, metabolic syndrome, depression and compromised immune function.

Vitamin D blood levels are affected by several intertwining factors that include age, race, type of skin, intake from food, sunlight exposure, geographical location, parathyroid hormone levels and obesity. It is also affected by the presence of pre-existing health conditions that compromise vitamin D absorption and metabolism, such as pancreatic, liver, kidney and bowel inflammatory diseases. There is emerging evidence that exercise affects vitamin D levels as higher vitamin D has been seen in individuals who exercise more frequently.

It is estimated that 70 percent of Americans are vitamin D insufficient. Under the watch of a health care professional, people with a low vitamin D level need to be on a vitamin D supplement. The recommended intake of vitamin D is 600 International Units (IU) per day for ages 1 to 70, including breastfeeding and pregnant women. People age 70 and older need 800 IU/day while newborns and children up to 12 months need 400 IU/day. 

However, there is no standard repletion and maintenance regimen that fits all. Supplementation is highly individualized and directed by your doctor. The best way to know if you need to be on a supplementation regimen is by checking your levels during your annual lab exams. The supplementation dose is based on the level of deficiency and the presence of pre-existing medical conditions. Once supplementation is started, the levels can be rechecked in six to eight weeks or per your doctor’s recommendation. 

When vitamin D levels are normal — with the absence of chronic diseases — intake of high vitamin D foods can be sufficient enough to maintain these levels. If you need to take calcium supplements, resort to the combined calcium-vitamin D brands. Natural vitamin D is found in very few foods and in limited amounts. However, fatty fish is considered a good source of natural vitamin D. Per a 3.5 oz serving:   herring contains 680 IU, salmon 360 IU, mackerel 234 IU, sardines 250 IU and tuna 200 IU. UV-B exposed mushrooms are also a good source of Vitamin D2, which contains up to 450 IU per 3.5 ounce.  Trace amounts are present in cheese, egg yolks and beef liver. Fortified foods, such as juices, milk, yogurt, margarine and breakfast cereals are good sources of vitamin D. It’s a good practice to read the food label so you know how much vitamin D and other nutrients you‘re taking in.

Levels below normal require the intake of extra vitamin D supplements. Vitamin D supplements are found in the two different forms: D2 (ergocalciferol) and D3 (cholecalciferol). Both forms share almost the same metabolic pathways and both increase vitamin D in the blood. However, vitamin D3 is preferred because it is more efficient in raising and maintaining vitamin D levels. Patients with end- stage renal disease might not get full benefit from these two forms and they need to be on the active form, called calcitriol.

Sunlight exposure is an excellent source of supplying adequate vitamin D, however, the exposure should be controlled and in moderation. It is evident that extensive exposure to UV radiation and developing sunburns as early as childhood age is associated with the development of cutaneous cancers and melanomas. The efficacy of adequate vitamin D production upon sunlight exposure could be limited by many factors, such as age, skin color, exposed body area, outdoor exposure time and the use of sunscreen SPF 8 and above. In optimal conditions, outdoor exposure for 10 to 15 minutes twice a week between 10:00 a.m. to 4:00 p.m. from mid-April to mid-October can form enough amounts of vitamin D to maintain normal levels. Developing the balance of adequate sun exposure while minimizing skin cancer risk is still under research. 

Betty Garrity

Coconut oil has become very popular in health food circles but is it really better than other oils? 

Betty Garrity MPH, RDN, director, UC San Diego Health Dietetic Internship

No. According to the American College of Cardiology, the National Lipid Association and the American Heart Association, we should be reducing intake of saturated fats. Coconut oil, like other tropical oils, such as palm and palm kernel oil, is high in saturated fatty acids, specifically lauric acid and myristic acid. These fatty acids are known to increase blood cholesterol levels, risk for cardiovascular disease and should be avoided. The lower the amount of saturated fat in our diet, the better.

Following a Mediterranean type eating pattern providing plenty Omega 3 fatty acids from fish and seafood (like salmon, sardines, tuna, herring and trout) twice weekly has multiple benefits. Research confirms fish or fish oil consumption can reduce inflammation, normalize heart function and reduce symptoms of rheumatoid arthritis, as well as stroke risk. 

Replacing coconut oil with small quantities of unsaturated fats, such as olive or canola oil, will lower cholesterol levels and decrease cardiovascular risk when consumed as part of a heart-healthy diet.  Emphasizing vegetables, fruits, fish, seafood, nuts, seeds and low-fat dairy products along with these unsaturated oils — used sparingly — better ensures heart-health and longevity.

Ann Roberts

What are some non-invasive ways of treating fibroid tumors?

Anne Roberts, MD, division chief, Vascular and Interventional Radiology

Traditionally, the treatment for symptomatic fibroids was a hysterectomy. There are now, however, non-surgical treatments that are much easier and safer for patients. The most common is a uterine artery embolization, which involves inserting a very thin tube into the blood vessel leading to the uterus. Very small particles are then injected into the blood vessel and carried into the fibroids, stopping blood flow to the mass. Without a blood supply, the fibroids shrink and symptoms are alleviated. More than 90 percent of patients will have partial or total relief of symptoms. Most patients are candidates for this procedure.

Another option is to use magnetic resonance (MR) imaging to very precisely and effectively heat and kill the fibroid tissue with a highly focused ultrasound beam. The MR-guided procedure is conceptually similar to burning a hole in a piece of paper by focusing a beam of sunlight with a magnifying glass. The fibroids do not disappear, but they often get smaller and the patient’s symptoms are improved. The procedure is done on an outpatient basis but may take four to five hours to complete. Not all patients are candidates for this procedure.

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