New light on an old vitamin: The role of the sunshine vitamin D in chronic disease

Abstract

As a child, I always enjoyed consuming milk products and more so as I grew and became active in athletics. One of my dynamic trainers, Dieter Roth, was responsible for leading me and my fellow athletes into Bavarian championships. I was fortunate to never have suffered a fracture from excessive running or weight training. Perhaps my daily vitamin D consumption helped in addition to genetics. I became interested in the science of vitamin D after encountering some patients with hypercalcemia [1]. During my tenure at the University of Mississippi, one of my mentees, Dr. M. Ullah, had expressed desire to explore the field of hypertension and I recommended that he review literature on the topic vitamin D and blood pressure regulation, resulting in several publications [2][3][4][5].My interest grew after I met a pregnant black African American woman that presented with nausea/vomiting, hypertension, a serum calcium of 14 mg/dl (elevated), parathyroid hormone (PTH) level of 102 pg/ml (elevated), and 25-hydroxy(OH) vitamin D level of 12 ng/ml. After hydration and a declining serum calcium to 10 mg/dl, she was prescribed oral vitamin D2 50,000 IU weekly and advised to follow-up. She had a history of noncompliance and (interestingly) took the prescribed vitamin D daily instead of weekly after discharge. She did not follow up in the antenatal or endocrine clinic as scheduled until 3 months later when she presented to the emergency room with headaches and elevated blood pressures (150-170 mm Hg systolic and 70-80 mm Hg diastolic). At this time, her serum calcium level was mildly elevated at 10.9 mg/dl, PTH was 49 pg/ml (inappropriately normal for the level of serum calcium) but the 25-OH vitamin D level was now very high (348.9 ng/ml). At 39 weeks of pregnancy, she had an elective Cesarean delivery of a healthy baby without further complications. The infant was monitored closely for 72 h for any signs of tetany, because of the mother's primary hyperparathyroidism which created a high risk for hypocalcemia. The serum calcium of the baby was normal (10.1 mg/dl) at birth and the baby remained completely asymptomatic at the time of discharge from the hospital, suggesting that at least one parathyroid gland of the baby was not suppressed in functionality, secreting PTH [6].To my knowledge, the highest reported 25-OH vitamin D level of Bvitamin D intoxication^due to food products or dietary supplements is 1482 ng/ml (3700 nmol/L). This has been treated with intravenous fluid hydration, administration of glucocorticoids, sodium phosphate, and bis phosphonates, without complications on 2 year follow-up (reviewed in Araki et al., ref. [7]). The second highest reported 25-OH vitamin D level is 1220 ng/ml (3045 nmol/L) and occurred in a 58-year old man with a concomitant serum calcium of 15 mg/dl (3.75 nmol/L). Symptoms included fatigue, excessive thirst, polyuria, and poor cognition. Utilizing liquid chromatography, tandem mass spectroscopy detected exclusively 25OHD3 and no 25OHD2. The man took multiple supplements with one labeled...

Pathogenetic role of vitamin D deficiency in the development of menstrual dysfunction in pubertal girls: a literature review

“…By all means, the prescription of low-and high-dose vitamin D should be considered individually, after detection of serum vitamin D and regular urine tests. With respect to the prevalence of the problem and proved correlation between vitamin D deficiency and various menstrual dysfunctions, screening is needed to reveal and prevent this disorder among girls at the age of puberty [32].…”

Primary Hyperparathyroidism and Hypercalcemia During Pregnancy

“…The outcome for both mother and fetus were favorable and the mother eventually underwent successful therapy for PHPT several months after her child birth. Several aspects of vitamin D including extraskeletal effects are reviewed in [23]. Mean 25-OH vitamin D levels are lower in black African American women compared to white women but vitamin D-binding protein concentrations in plasma are similar in black and white women unrelated to body mass index in either racial group [24].…”