My doctor just called, and last week’s yearly blood work shows that I have a significant deficiency in Vitamin D. How did this happen? I suspect it’s something to do with having to take a prescription medicine that caused me an uncomfortable sun-related rash while enjoying myself watching a baseball game while on vacation in Florida. Since that painful incident I’ve become much more vigilant about staying out of the sun, but now I’m experiencing the results of that choice.
Vitamin D is a fat-soluble vitamin that is important in maintaining the strength of our muscles and bones. We get Vitamin D from diet, sun exposure, and supplements.
Vitamin D is called the “Sunshine Vitamin” because our bodies generate it when our skin is exposed to UVB rays in direct sunlight. You are most likely to be deficient in Vitamin D if you are elderly, have dark skin, or, like me for the past year and a half , spend little time outside in the sun without covering up or wearing sunscreen.
Vitamin D deficiency can also be from not being able to absorb fat-soluble vitamins, which can happen after having gastric bypass surgery, inflammatory bowel disease, or taking medicines like prednisone or the weight loss agent Alli®.
As we age, we’ll need more Vitamin D, because our skin is less able to make it from sun exposure and our kidneys become less efficient in changing it into its most active form. Although I’m only in my mid-fifties, I’m not alone in needing more Vitamin D. Over 50% of our elders in America are estimated to have Vitamin D deficiency, which has been linked to muscle weakness, falling, and an increased risk of breast, prostate, pancreatic, colon and ovarian cancers. Replenishing body stores of Vitamin D with supplementation has been shown to improve muscle strength and balance and to decrease the incidence of falls in elderly Americans by at least 20%.
Unfortunately,as I found out, it’s hard to get enough Vitamin D from what you eat. The best dietary source is fatty fish such as salmon, canned tuna and sardines, which have about 300 units of Vitamin D per 3.5 ounce serving. The next best source is fortified milk, which has up to 100 units per cup of added Vitamin D. Milk was fortified in the United States beginning in the 1930s to combat rickets, a deficiency of Vitamin D in children that caused soft bones and deformed legs. One of the most memorable and concentrated sources of Vitamin D is cod liver oil, with 1300 units per tablespoon. Thanks, I’ll pass on that…
How did I find out I needed Vitamin D supplementation? By a blood test last week that measures 25-hydroxyvitamin D in the body. If the level is less than 30, you are considered Vitamin D deficient and a 8-12 week course of prescription Vitamin D supplementation at 50,000 units once weeky is usually prescribed, with a maintenance dose of 1000 to 2000 units daily after that. My Vitamin D level was only 13, and I have just started taking 50,000 units every week of a prescription of Vitamin D supplement.
Vitamin D supplements come in both prescription and non-prescription strengths. There are 3 forms of Vitamin D available: D2, called ergocalciferol, D3, called cholecalciferol, and calcitriol. These are available without a prescription in several strengths, from 400 up to 4000 units. D3, also called cholecalciferol, is best one at maintaining your Vitamin D.
I’ve just started taking 50,000 units of ergocalciferol ( Vitamin D2), every week for 12 weeks, after which I’ll get another blood test to see if I’ve responded to that. If my level hasn’t risen to at least 30, I’ll be repeating the weekly supplementation for another 12 weeks. Once I get back into the normal range, I should be able to maintain my level with about 2,000 units of D3 every day, from either sun, diet or supplements.
Because I need to continue taking the medicine that caused me the sun reaction in Florida, I’m probably stuck taking a Vitamin D supplement from now on. Most women over 50 years old should take a calcium supplement with at least 800 units Vitamin D daily anyway, to help their body use that calcium to strengthen their bones. Because I already take a calcium supplement containing 800 units of Vitamin D, eventually I’ll need at least 1000 units of additional Vitamin D as Vitamin D3 daily. Choosing Vitamin D3 (cholecalciferol) for long term maintenance seems to maintain your levels better than taking Vitamin D2.
Dr. Louise Achey, Doctor of Pharmacy is a 30 year veteran of pharmacology. Please send questions and comments to www.AskDrLouise.com.
