Chinese women in tropics needed 50,000 IU of Vitamin D monthly to keep above 30 ng – RCT

Created July 2017

Maintenance vitamin D3 dosage requirements in Chinese women with post menopausal osteoporosis living in the tropics.

Asia Pac J Clin Nutr. 2017 May;26(3):412-420. doi: 10.6133/apjcn.042016.10.

97% of Chinese Women living in the tropics who previous to the trial already had > 30ng level of Vitamin D needed 50,000 IU to maintain it. More Vitamin D would be needed for women starting with < 30 ng level.--- 1. See also Vitamin D Life* One pill every two weeks gives you all the vitamin D most adults need* 50,000 IU TWICE a month* Much more than 2,000 IU of vitamin D is needed daily (Middle East studies agree) – meta-analysis Nov 2016* 2000 IU of vitamin D- doctors trained that it was too much, but it is often too little* 30 percent of vitamin D sold now has more than 2000 IU - Dec 2012* European adults can take 4000 IU of vitamin D – July 2012* = 2.8 capsules of 50,000 per month* 50,000 IU of vitamin D every two weeks – Jordan conclusion - RCT July 2017

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Venugopal Y1, Hatta SFWM2, Musa N2, Rahman SA2, Ratnasingam J2, Paramasivam SS2, Lim LL2, Ibrahim L2, Choong K2, Tan AT2, Chinna K2, Chan SP2, Vethakkan SR2.

1 Department of Medicine, University of Malaya, Lembah Pantai,59100 Kuala Lumpur,Malaysia. Email: [email protected]; [email protected].
2 Department of Medicine, University of Malaya, Lembah Pantai,59100 Kuala Lumpur,Malaysia.

BACKGROUND AND OBJECTIVES:

Vitamin D3 (cholecalciferol) dose required to maintain sufficiency in non- Caucasian women with postmenopausal osteoporosis (PMO) inthe tropics has not been well studied. Some guidelines mandate 800-1000 IU vitamin D/day but the Endocrine Society (US) advocates 1500-2000 IU/day to maintain 25-hydroxyvitamin-D (25(OH)D) concentration at >75 nmol/L. We aimed to establish oral cholecalciferol dose required to maintain 25(OH)D concentration at >75 nmol/L in PMO Chinese Malaysian women, postulating lower dose requirements amongst light-skinned subjects in the tropics.

METHODS AND STUDY DESIGN:

90 Chinese Malaysian PMO women in Kuala Lumpur, Malaysia (2°30'N) with baseline serum 25(OH)D levels >=50 nmol/L were recruited. Prior vitamin D supplements were discontinued and subjects randomized to oral cholecalciferol 25,000 IU/4-weekly (Group-A) or 50,000 IU/4-weekly (Group- B ) for 16 weeks, administered under direct observation. Serum 25(OH)D, PTH, serum/urinary calcium were measured at baseline, 8 and 16 weeks.

RESULTS:

Baseline characteristics, including osteoporosis severity, sun exposure (~3 hours/week), and serum 25(OH)D did not differ between treatment arms. After 16 weeks, 91% of women sufficient at baseline, remained sufficient on 25,000 IU/4-weekly compared with 97% on 50,000 IU/ 4-weekly with mean serum 25(OH)D 108.1±20.4 and 114.7±18.4 SD nmol/L respectively (p=0.273). At trial's end, 39% and 80% of insufficient women at baseline attained sufficiency in Group A and Group B (p=0.057). Neither dose was associated with hyperparathyroidism or toxicity.

CONCLUSIONS:

Despite pretrial vitamin D supplementation and adequate sun exposure, 25.6% Chinese Malaysian PMO women were vitamin D insufficient indicating sunshine alone cannot ensure sufficiency in the tropics. Both ~900 IU/day and ~1800 IU/day cholecalciferol can safely maintain vitamin D sufficiency in >90% of Chinese Malaysian PMO women. Higher doses are required with baseline concentration <75 nmol/L.

PMID: 28429905