Table 1 Examples of regimes for treating simple vitamin D deficiency (deficiency secondary to inadequate sunlight exposure or dietary intake), and maintenance supplementation.

Treatment of vitamin D deficiency

ergocalciferol 250 μg (10,000 IU) once daily

10,000 IU vitamin D

Supply problem in the UK.

ergocalciferol 1.25 mg (50,000 IU) once weekly

7,000 IU vitamin D

Supply problem in the UK.

intramuscular ergocalciferol or colecalciferol 7.5 mg (300,000 IU) monthly

10,000 IU vitamin D

Injection may be unpopular. Supply problem in the UK.

paediatric ergocalciferol solution (3,000 IU/ml), 3 ml daily

9,000 IU vitamin D

Special supply arrangements may be required. Excipients may include peanut oil.

colecalciferol 500 μg (20,000 IU) 3–4 times per week

8,600–11,400 IU vitamin D

Available from overseas suppliers.

colecalciferol liquid, e.g. 2,000 IU/ml, 5 ml daily

10,000 IU vitamin D

Custom strengths available as 'special' orders in the UK.

commercial 'high strength' (25 μg; 1,000 IU) colecalciferol, two tablets twice daily

4,000 IU vitamin D

Available from high street health food suppliers including online.

colecalciferol 25 μg (1,000 IU), two tablets twice daily, plus compound calcium (500 mg) with ergocalciferol or colecalciferol (400 IU), one tablet twice daily

4,800 IU vitamin D

1,000 mg calcium

Includes sufficient calcium to ensure adequate total intake (though calcium supplements may have low palatability).

compound calcium (500 mg) with ergocalciferol or colecalciferol (400 IU), two tablets twice daily, plus generic multivitamins (including 300 IU vitamin D), two capsules twice daily

2,800 IU vitamin D

2,000 mg calcium

10,000 IU vitamin A (3,000 μg RE)

60 mg ascorbic acid

30 mg nicotinamide

2 mg riboflavin

4 mg thiamine

Not ideal. Vitamin D dose lower than recommended treatment regimens. Many tablets required. Calcium content gives poor palatability and may cause gastrointestinal side effects in a few patients [37]. The vitamin A dose may be close to a prudent threshold for teratogenicity, and exceeds the maximum dose recommended for long-term use (1,500 μg RE/day); higher doses are associated with increased risk of hip fracture [37]. No other component is likely to produce toxicity at this dose [37].

1-hydroxylated derivatives of vitamin D (e.g. alfacalcidol, dihydrotachysterol, calcitriol)

--

Not recommended. Does not treat vitamin D deficiency. Higher potential for toxicity. Greater need for monitoring. Few reasons to use, unless severe renal disease or hypocalcaemia [31–34].

Maintenance supplementation (examples)

ergocalciferol 1.25 mg (50,000 IU) every 2–4 weeks or monthly

1,640–3,570 IU vitamin D

Supply problem in the UK.

colecalciferol 25 μg (1,000 IU) daily

1,000 IU vitamin D

--

compound calcium (500 mg) with ergocalciferol or colecalciferol (400 IU), one tablet twice daily

800 IU vitamin D

1,000 mg calcium

Includes sufficient calcium to ensure adequate total intake.

Additional non-pharmacological options

sunlight exposure (0.5 minimal erythemal dose daily, e.g. 5–10 minutes of exposure of arms and legs to direct sunlight)

3,000 IU vitamin D [1]

Excessive exposure predisposes to skin cancer. Latitude, season, time of day and weather alter incoming radiation dose; age and skin pigment alter efficacy.

cod liver oil (5 ml/day)

400–1,000 IU vitamin D [1]

2,400–15,600 IU vitamin A (720–4,700 μg RE) [38]

other constituents including Ω-3 fatty acids

Caution advised in asthma and pregnancy and in patients on warfarin [39]. May convey other health benefits. Some preparations can contain high doses of vitamin A, which may be disadvantageous (see above).

oily fish (two portions of 100 g per week)

70–285 IU vitamin D [1]

other constituents including Ω-3 fatty acids

May convey other health benefits.