What Is the “Sunshine” Vitamin? All About D3 Post-WLS

Article By: Rachel Ignomirello, MS, RDN, CSOWM, LDN

Rachel Ignomirello is a Bariatric Dietitian and Board-Certified Specialist in Obesity and Weight Management.

Vitamins are a forever commitment after metabolic and bariatric surgery. The body cannot absorb nutrients the same, so serious complications can arise with supplement non-compliance. One of the most common deficiencies, and therefore one of the most important nutrients, is Vitamin D.

1) What is Vitamin D? Vitamin D (also called calciferol) is one of the fat-soluble vitamins. The two main forms of Vitamin D are D3 (cholecalciferol) and D2 (ergocalciferol). The body may absorb D3 slightly better than D2, but either type will provide enough of the nutrient. The main purpose of Vitamin D is to help absorb and utilize Calcium, which is the mineral that supports bone strength, nerve conduction, and muscle contraction. Together with Calcium, Vitamin D reduces the risk of osteopenia (low bone density) and osteoporosis (a disease that weakens bone). Vitamin D also boosts the immune system to help ward off infection.

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2) Why is Vitamin D called "the sunshine vitamin"? When bare skin is exposed to sunlight, the ultraviolet (UV) light makes Vitamin D3 from cholesterol in the body. Most people get some Vitamin D this way, but dark-colored skin, cloud coverage, and smog will reduce this synthesis. Sunlight through a window cannot produce Vitamin D either. UV light can cause skin cancer, so it is important to limit sun exposure. Many studies suggest only getting 15 minutes of sun exposure before putting on quality sunscreen.

3) What foods provide Vitamin D? The answer is not many. Very few foods naturally contain Vitamin D. The top three sources include cod liver oil, rainbow trout, and sockeye salmon. The other top sources come from fortified foods, which is how most Americans get their Vitamin D. Those foods include mushrooms (exposed for UV light), fortified milks, and fortified ready-to-eat cereal. Vitamin D is required on Nutrition Facts Labels, so amounts can be found on food and drink packages.

4) What are the signs & symptoms of Vitamin D deficiency? The American Society for Metabolic and Bariatric Surgery (ASMBS) reports that Vitamin D deficiency prevalence is as high as 90% in patients with obesity. Fat cells hold onto Vitamin D and prevent its release. Early deficiency signs include bone pain, muscle weakness, fatigue, and mood changes, which could all easily be ignored in bariatric populations. The best way to check Vitamin D levels is to have your provider order a blood test. Optimal serum Vitamin D levels should be at least 30. If the amount of Vitamin D in the blood is 20-29, the level is determined to be insufficient. If the amount is below 20, that is a deficiency.

5) How much Vitamin D is needed? Prior to bariatric surgery, the average adult needs around 15 micrograms (mcg) or 600 International Units (IU) of Vitamin D. Per ASMBS guidelines, bariatric patients should take a preventative dose of 3,000 IU daily. This amount is often provided in bariatric multivitamins, and D3 is usually the form used. More may be required if serum blood levels of Vitamin D are not greater than 30. For example, providers may encourage 5,000 IU for insufficiency or even a megadose of 50,000 IU for deficiency. To boost absorption, a Vitamin D supplement should be taken with a meal or snack that contains some dietary fat. Just don’t take a megadose on your own since too much Vitamin D can be stored in the body and therefore harmful.

BariMelts provides general recommendations, not to be construed as medical advice. Please consult your doctor.