Is it Fibromyalgia or Osteomalacia?
ADVANCED PRACTICE
“Three things cannot be long hidden: the sun, the moon, and the truth.” — Buddha
Alan Cook
DC
How many patients have you seen with a diagnosis of fibromyalgia? It hurts here and there, often, and for no apparent reason.
The convenient but minimally helpful diagnosis of fibromyalgia literally means:
Fibro = fibrous tissue Myo = muscle Algia = pain
Putting this simply, your patient aches in many places. Symptoms that are often described or attributed to fibromyalgia include:1
• Muscle pain, burning, twitches, tightness • Tender or trigger points • Fatigue
• Trouble concentrating or impaired memory (some times called “fibro fog”)
• Insomnia • Depression
The symptoms are similar to other conditions that should be considered and tested. These include hypothyroidism, various arthritides, lupus, and hormonal changes.2
Neither blood tests nor imaging point directly to fibromyalgia. Instead, it’s a diagnosis of exclusion or a way for a provider to answer the question of “What’s wrong?” when they don’t really know.
With diagnosis rendered, it’s time for treatment. The medications that are recommended are from the following classes: antidepressants, antiseizure, pain relievers, muscle relaxants, and sleep aids.3
Recommendations from providers who emphasize diet and natural compounds may include:4
• Green vegetables — a source of magnesium as well as other minerals • Lean protein
• Fermented foods/cultured dairy — sources of probiotics
• Omega-3 fatty acids — healthy fats to reduce in flammation
• Antioxidants — beta carotene, vitamin C, vitamin E
But is the source of these nonspecific symptoms really fibromyalgia? Or could the generalized aches with the consequent poor sleep lead to depression and “fog?” Or does depression increase pain sensitivity?
Osteomalacia
Osteomalacia means literally “bad bone.” Poor-quality bone is softer because of a deficiency of calcium or, more commonly, vitamin D. In children, vitamin D deficiency causes rickets. In adults, it is called osteomalacia. Inadequate vitamin D causes bones to soften, making them ache and more prone to fracture.5
• Symptoms of osteomalacia may included
• Vague muscle and bone aches
• Increased susceptibility to fracture
• Muscle weakness
Due to the vague and nonspecific symptom picture, vitamin D deficiency frequently escapes recognition, especially in the early presentation.7 The signs of vitamin D deficiency may include:5
• Hypocalcemia
• Elevated alkaline phosphatase
• Decreased bone mineral density on a DXA examination
• Low serum 25-hydroxycholecalciferol
The blood test is for vitamin D is 25-hydroxycholecalciferol — the storage form. Following are the most common laboratory thresholds.8
When looking at the blood levels of non-Westernized societies (e.g., Masai tribe), it’s common to see a level of 60 ng/ml.9 Many vitamin D researchers suggest that optimal levels should be >50 ng/ml.10 These are substantially higher than the 30 ng/ml threshold reported as normal.
Iatrogenic Vitamin D Deficiency
A number of drugs are known to interfere with vitamin D metabolism.11 The following table is arranged with the greatest to least negative.
The natural compounds kava kava and St. John’s wort can similarly decrease vitamin D levels.11
Interruptions in vitamin D metabolism are not trivial. During long-term glucocorticoid therapy, 30 to 50% of patients develop osteoporosis, increasing with greater dose or duration.12 Ninety-one percent of HIV-positive patients taking antiretrovirals who were studied had suboptimal vitamin D levels, with one-third having a severe deficiency.1314 Up to 50% of patients taking long-term antiseizure medications will develop bone disease with fracture risk increasing two to six times higher compared with the average population.1516
How to Begin
When a patient comes to your office reporting general muscle/bone aches, weakness, sleep disturbance, or stating they have fibromyalgia, consider that it may be unrecognized vitamin D deficiency causing osteomalacia.
The first step is to order lab tests:
• Complete metabolic panel (must include serum calcium, alkaline phosphatase, liver, and kidney tests)
• Vitamin D 25-hydroxycholecalciferol level
Also, consider ordering a DXA (bone density) study.
When a patient has low vitamin D, low serum calcium, high alkaline phosphatase, and low bone mineral density, it is likely osteomalacia.5 6 Though bone biopsy is the most definitive test for osteomalacia,17 it is rarely done because it is too painful. If osteomalacia is suspected, the recommendation is to just begin vitamin D treatment.
Osteomalacia versus Osteoporosis
Osteoporosis may be confused with osteomalacia. The normal human skeleton is composed of mineral components, including calcium hydroxyapatite (60%) and organic material, mainly collagen protein (40%).18
With osteoporosis, bones are porous and brittle, whereas, with osteomalacia, bones are soft. This difference in bone consistency is related to the mineral-to-organic material ratio. With osteoporosis, the mineral-to-collagen ratio remains in normal reference range. With osteomalacia, the proportion of mineral composition is reduced relative to organic matrix.18
Once the presence of vitamin D deficiency is established, the question of how much to prescribe becomes primary. In discussing vitamin D and dosage, consider that there are three sources: sunshine-skin, food, and supplements.5
Sunshine-skin contributions are limited if your patient lives and works indoors, avoids sunshine, uses sunscreen, or has dark or aged skin. The main food sources of vitamin D include fish (especially wild-caught salmon and herring), oysters, and liver. If your patient does not eat these foods nor is exposed to the sun regularly, they need supplementation.5
Here too, there is no one answer. With a known deficiency, the combined vitamin D sources of sunshine, food, and supplements should add to at least 5,000 IUs (125 meg) per day. Because vitamin D is fat-soluble, obese patients will require two to three times the suggested 5,000 IUs.5 Another researcher suggested 7,000 IU/day/12 weeks followed with a retest.19
Vitamin D insufficiency and deficiency are widespread.20 The implications of deficiency are numerous. Osteomalacia, directly attributable to vitamin D deficiency, is often an overlooked source of aches and pains, as well as muscle weakness.
Summary
The symptoms of osteomalacia and fibromyalgia have significant overlap. Since there are no identifying lab or imaging tests, fibromyalgia is a diagnosis of exclusion.
Osteomalacia can be suspected in a symptomatic patient with low serum 25-hydroxycholecalciferol, low serum calcium, and/or high alkaline phosphatase. Osteomalacia can be directly attributed to vitamin D deficiency.
Treating a known vitamin D deficiency requires relatively large doses; 5,000-7,000 IU/day/12 weeks followed by a retest. If the patient is obese, the dose should be increased twoto threefold.
An incorrect diagnosis of fibromyalgia is a missed opportunity to treat the cause of pain. Vitamin D is not prescribed for fibromyalgia, though it is required for osteomalacia. Wrong treatment for the wrong diagnosis with a predictable outcome of no improvement.
Alan Cook, DC, has been in practice since 1989. He ran the Osteoporosis Diagnostic Center (1996-2019), participated in four clinical trials, and lectured nationally. He currently works with the Open Door Clinic system in a multidisciplinary setting and provides video-based continuing education with EasyWebCE. To see more of his work, log onto: www.EasyWebCE.com
References
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5. Holick MF. Resurrection of vitamin D deficiency and rickets. J Clin Invest. 2006; 116(8):2062-20 72.
6. Gough KR, Lloyd OC, Willis MR. Nutritional osteomalacia. Lancet 1964;2:1261-64.
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9. LuxwoldaMF, Kuipers RS, Kema IP, Dijck-Brouwer DA, Muskiet FA. Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/1. Br J Nutr. 2012;108:1557-61.
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11. Grober U, Kisters K. Influence of drugs on vitamin D and calcium metabolism. Dennatoendocrinol. 2012 Apr 1;4(2): 158-66. doi: 10.4161/derm.20731. PMID: 22928072; PMC ID: PMC3427195.
12. Kanis JA, Johansson H, Oden ,4, Johnell O, de Laet C, Melton U, III, et al. A meta-analysis ofprior corticosteroid use and fracture risk. J Bone Miner Res. 2004;19:893-9. doi: 10.1359/JBMR.040134.
13. Brown TT, Oaqish RB. Antiretroviral therapy and the prevalence of osteopenia and osteoporosis: a meta-analytic review. AIDS. 2006;20:2165-74. doi: 10.109 7/0AD. 0b013e32801022eb.
14. Welz T, Childs K, Ibrahim F, Poulton M, Taylor CB, Moniz CF, et al. Efavirenz is associated with severe vitamin D deficiency and increased alkaline phosphatase. AIDS. 2010;24:1923-8. doi: 10.1097/OAD.0b013e32833c3281.
15. J alsamis HA, Arora SK, Labban B, McFarlane SI. Antiepileptic drugs and bone metabolism. NutrMetab (Lond) 2006;3:36. doi: 10.1186/1743-7075-3-36.
16. Vestergaard P, Rejnmark L, Mosekilde L. Fracture risk associated with use of antiepileptic drugs. Epilepsia. 2004;45:1330-7. doi: 10.1111/j.00139580.2004.18804.x.
17. Bingham CT, Fitzpatrick LA. Noninvasive testing in the diagnosis of osteomalacia. Am J Med. 1993;95:519-523.
18. Russell DA. Osteoporosis and Osteomalacia. Rheumatic Disease Clinics 2010;36:665-680.
19. Khan OJ, Reddy PS, Kinder BF, Sharma P, Baxa SE, O DeaAP, et al. Effect of vitamin D supplementation on serum 25-hydroxy vitamin D levels, joint pain, and fatigue in women starting adjuvant letrozole treatment for breast cancer. Breast Cancer Res Treat. 2010; 119:111-8. doi: 10.1007/sl0549-009-0495-x.
20. Hanley DA, Davison KS. Vitamin D Insufficiency in North America. J Nutr. 2005;135:332-337.
