Can I Take Vitamin D with Egrifta (Tesamorelin)?

Does vitamin D interact with Egrifta?

Egrifta SV is a growth hormone-releasing factor analog approved for reduction of excess abdominal fat in HIV-infected adults with lipodystrophy [1]. The drug interactions section of the Egrifta SV label lists two categories: drugs metabolized by CYP450 enzymes and glucocorticoids [1]. The Egrifta WR label lists the same two categories [2]. Vitamin D is not named in either Egrifta interaction section [1][2]. That does not prove the pair is safe; it is only what the labels state.

Over-the-counter vitamin D products are dietary supplements, not FDA-approved drugs. Prescription ergocalciferol capsules also exist for hypoparathyroidism, refractory rickets and familial hypophosphatemia [5][6]. Vitamin D is sold as D3 (cholecalciferol) and D2 (ergocalciferol) [5].

What does the Egrifta label say to monitor?

Tesamorelin raises IGF-1. The label says to monitor IGF-1 and consider discontinuing in patients with persistent elevations, for example above 3 SDS, especially if fat loss is not robust [1]. It also says the effects of prolonged IGF-1 elevation are unknown [1].

The label says to evaluate glucose before and during therapy [1]. By week 26, HbA1c of 6.5% or higher developed in 5% of patients on tesamorelin and 1% on placebo, with a hazard ratio of about 3.3 (95% CI 1.4 to 9.6) [1].

Do you need vitamin D testing or extra supplements?

For people without an established indication for vitamin D treatment or testing, the 2024 Endocrine Society guideline suggests against routine 25(OH)D testing [5]. It also suggests against empiric supplementation above the dietary reference intake in healthy adults younger than 75 [5]. The guideline does not apply to people with an established indication for treatment or testing [5].

How much vitamin D is too much?

The RDA for vitamin D is 600 IU/day (15 mcg) for ages 1 to 70, including pregnancy and lactation, and 800 IU/day (20 mcg) for ages 71 and older [4]. The tolerable upper intake level for adults and teens 9 years and older is 4,000 IU/day (100 mcg) [3]. The UL is not a target intake [3].

Toxicity is rare and usually comes from very large doses or manufacturing errors [7][8]. A 25(OH)D above 150 ng/mL (375 nmol/L) is the hallmark of toxicity from overdosing [7]. Symptoms include confusion, apathy, recurrent vomiting, abdominal pain, polyuria, polydipsia and dehydration [7]. The prescription ergocalciferol label says the range between therapeutic and toxic doses is narrow [6].

Does vitamin D form or timing matter?

A meta-analysis of randomized trials found that D3 raised 25(OH)D more than D2 overall, but the difference came from bolus dosing and was lost with daily supplementation [9].

In a 90-day randomized trial of 62 healthy older adults, a monthly 50,000 IU D3 dose taken with a high-fat meal, a low-fat meal or no meal produced no difference in 25(OH)D at 30 or 90 days, although a low-fat meal increased short-term D3 absorption [10].

What about prescription vitamin D?

Prescription ergocalciferol capsules are labeled for hypoparathyroidism, refractory rickets and familial hypophosphatemia [6]. The labeled doses are 12,000 to 500,000 USP units daily for resistant rickets and 50,000 to 200,000 units daily for hypoparathyroidism, with blood calcium and phosphorus checked every 2 weeks [6]. The label does not list vitamin D deficiency or insufficiency as an indication [6].

What the Egrifta label lists as warning signs

Hypersensitivity reactions occurred in 4% of patients treated with Egrifta in clinical trials, including itching, redness, flushing, hives and rash [1]. The label says to seek immediate medical attention and stop treatment if a hypersensitivity reaction is suspected [1].

Injection-site reactions occurred in 25% of tesamorelin-treated patients and 14% of placebo-treated patients during the first 26 weeks [1]. Fluid retention may include edema, joint pain and carpal tunnel syndrome [1].